Why We Keep Mugs We Don't Use (And Other Questions About Ourselves We'd Rather Not Answer)

I was cleaning out my desk drawer three months ago when I found my old Certified ScrumMaster certificate.¹ Laminated. Framed, even.² I hadn't thought about Scrum in years. My job at the time abandoned those ceremonies sometime in 2013 when everyone silently agreed the retrospectives had become performance art.³ Still, I couldn't throw the certificate away.

It sat there in my hand for a solid minute. This piece of paper represented four hundred dollars, two days of training, and what I'd convinced myself was a pivotal moment in my professional development. Throwing it away felt wrong. Wasteful. The certificate had value because it was mine, because I'd earned it, because disposing of it would somehow invalidate the person who'd worked to get it.

Then I had a thought so obvious it was embarrassing: If this certificate appeared in my mailbox tomorrow, completely unsolicited, would I frame it and keep it on my desk?

No. Absolutely not. I'd probably recycle it with the grocery store circulars.

So why couldn't I throw away the one I already owned?

The Experiment You've Been Running on Yourself

In 1990, three behavioral economists (Richard Thaler, Daniel Kahneman, and Jack Knetsch) ran an experiment so simple it's almost insulting.⁴ They gathered participants and split them into two groups (Buyers and Sellers). The first group received a coffee mug and were told they owned it. The second group got nothing but were told they could buy a mug if they wanted.

The researchers then asked what seems a straightforward question. Sellers: what's the minimum price you'd accept to part with your mug? Buyers: what's the maximum you'd pay to acquire one?

The mugs were identical. Mass-produced. Unremarkable in every measurable way.

Sellers wanted an average of seven dollars. Buyers offered three.

Same mug. Different ownership status. More than double the perceived value.

The researchers called this the Endowment Effect.⁵ We assign inflated value to things simply because we possess them. Ownership creates attachment. Attachment creates irrationality. Your brain treats letting go of something you own as a loss, even when keeping it provides no actual benefit.

Think about what you're holding onto right now.

Not just physical objects. This mental inventory is where things get interesting.

The Professional Development Trap⁶

Here's where it gets uncomfortable for those of us who've spent careers climbing corporate ladders or building expertise.⁷

You spent three years learning that programming language. You invested in that certification. You developed proficiency in that methodology. You built your professional identity around that skill set. These things became yours, became you, became the coffee mug you're clutching while the market moves on.

When was the last time you audited your professional commitments with genuine honesty? I'm not talking about the annual performance review where you list accomplishments and set goals. I mean a harder question: if you were starting your career today, with everything you know now, would you choose to invest time in the things currently filling your calendar?

Would you join that committee? Attend that recurring meeting?⁸ Maintain that system? Pursue that certification? Build expertise in that particular toolset?

Or are you just showing up because you've always shown up, because walking away feels wasteful, because the sunk cost of your past investment makes you value the future returns more than they're worth?

The research is clear. You're probably overvaluing these commitments by a factor of two or more. Maybe three. Maybe ten, depending on how long you've been holding on.

The Seven-Year Itch Has Nothing on Biology

Your body replaces approximately 330 billion cells every day.⁹ Skin cells turnover every two to four weeks. Red blood cells last about four months. Your entire skeleton rebuilds itself every decade.

You are literally not the same person who started reading this sentence.¹⁰ The atoms composing your body right now will be someone else's atoms eventually, scattered into soil or water or air, indifferent to the concept of ownership.

Nature has no Endowment Effect. Biology doesn't get sentimental. The old gets shed. The new gets built. The process continues whether you're paying attention or not.

So why do we cling so desperately to the career moves, the relationships, the commitments, the identities we built five years ago? Ten years ago? Twenty?

The tools that got you here aren't necessarily the ones you need for where you're going. The skills valuable in 2015 might be maintenance overhead in 2025. The professional network you cultivated could be reinforcing outdated assumptions. The goals you set when you were someone else might not serve who you're becoming.

The Question Nobody Wants to Ask¹¹

If you didn't already have this job, this commitment, this goal, this identity, would you choose it today?

Not "could you make it work." Not "is it fine enough." Not "well, it's complicated." Would you actively choose it?

The answer reveals a struggle you aren't consciously aware of. You're probably holding onto things because letting go feels costly, not because keeping them provides value. The Endowment Effect isn't helping you. It's keeping you stuck.

Consider your current role. If you were unemployed tomorrow and saw this position listed, would you apply? Would you angle for an interview? Would you negotiate hard for the offer? Or would you scroll past, maybe bookmark it as a backup option, ultimately decide it's not quite right?

What about your goals? If someone else described their ambitions to you, and those ambitions matched yours exactly, would you encourage them? Would you think "yes, that's a worthy pursuit" or would you gently suggest they might want to reconsider?

Your relationships, your possessions, your habits, your beliefs about yourself. Run them through the filter. If you encountered these fresh, unencumbered by history and identity and the story you tell yourself about who you are, would you choose them?

The Unbecoming

Nobody tells you the hardest part of growth is subtraction.¹² We're sold on addition. Learn more skills. Build more connections. Acquire more credentials. Stack more achievements. Become more impressive.

But the mathematics of personal development doesn't work on addition. It works on replacement. Something has to go before something else can arrive.

You can't become the person you need to be while dragging along everything the old version accumulated. The weight makes you slow. The attachment makes you rigid. The seven-dollar coffee mug you're clutching because you've always clutched it prevents you from picking up something actually useful.

This applies professionally as much as personally. Maybe more. Work gives us identity in ways we don't always acknowledge. The skills we've mastered become who we are. The roles we've held become how we introduce ourselves.¹³ The methods we've perfected become the hill we'll die on in planning meetings.

Letting go means admitting the time invested might not pay future dividends. It means acknowledging the past version of yourself made the best decisions with available information, and the current version has different information now. It means treating your career as biology treats your cells: constant replacement, no sentimentality, forward motion.

The Replacement Principle

Your body doesn't ask permission before shedding cells. It doesn't deliberate. It doesn't get nostalgic about the epidermis from last Tuesday. The old goes, the new arrives, life continues.

What would happen if you approached your professional development with similar ruthlessness?

Not careless abandonment. Not impulsive decisions. But a clear-eyed assessment of what you're carrying and why you're carrying it. An honest inventory of the commitments filling your calendar. A genuine question about whether the goals you're pursuing belong to present-you or past-you.

Strip away the Endowment Effect and you might discover you're holding onto relationships because ending them feels painful, not because maintaining them provides joy. You might realize you're defending methodologies because you invested time learning them, not because they're still optimal. You might notice you're pursuing goals because you announced them publicly, not because they align with who you're becoming.

The person you were when you started is not the person you need to be when you finish. Something has to change. Usually, that something is you.

The question isn't whether you'll evolve. Biology guarantees transformation whether you participate consciously or not. The question is whether you'll direct the process or let inertia and the Endowment Effect make decisions for you.

What are you holding onto because you own it rather than because it serves you?

What would you let go if you could see it clearly, unencumbered by the story of how hard you worked to get it?

Who could you become if you weren't so attached to who you've been?

The coffee mug sits on my desk still.¹⁴ Not the ScrumMaster certificate. That went in recycling about thirty seconds after I asked myself the right question. But there's always another mug. Another certification. Another commitment. Another version of yourself you've outgrown but keep carrying anyway.

Your body already knows what to do. Maybe it's time you learned from it.

¹ The cliché of discovering something meaningful while cleaning is not lost on me. Next I'll be finding old photographs in the attic or stumbling across my grandfather's journal. But this actually happened, which is either proof that clichés exist because they're true or proof that my life has become derivative.

² The framing was perhaps the most damning part. Who frames a professional certificate except someone desperately trying to convince themselves and others it matters? I might as well have hung my high school diploma next to it. Actually, I don't know where my high school diploma is. That's probably worth examining.

³ You know the exact moment a workplace practice dies: when people start using air quotes around its name. "We have our 'retrospective' today." The scare quotes are a eulogy. The practice is already dead. You're just still holding the funeral services every two weeks because nobody wants to be the one to officially cancel it.

⁴ Thirty-five years ago. The research predates the internet, smartphones, and the concept of a "side hustle." Yet somehow these three economists with their coffee mugs understood something about human nature we're still struggling to apply. This should tell you something about either the persistence of cognitive biases or our collective inability to learn from social science. Possibly both.

⁵ The official academic term, which sounds vaguely medical. "I'm sorry, Mr. Johnson, but you've tested positive for Endowment Effect. I'm afraid it's chronic. We can manage the symptoms but there's no cure." At least it sounds more respectable than "you irrationally value your stuff."

⁶ I'm using section headers in this essay, which feels slightly cheap. Like I'm trying to make it easier to scan. The irony of writing about letting go of things while clinging to conventional essay structure is not lost. Then again, maybe some structures actually serve their purpose. Or maybe I'm just experiencing the Endowment Effect about essay formatting.

⁷ Which, let's be honest, is most of us reading this. We didn't stumble into personal development essays by accident. We're here because we've invested time and energy into becoming "better," whatever we think that means. We're probably overvaluing that investment too.

⁸ The recurring meeting might be the purest expression of the Endowment Effect in modern corporate life. Tuesday at 2pm, every week, forever. Nobody remembers why it started. The original purpose dissolved years ago. But canceling it would require someone to admit those 52 hours per year (per attendee!) could be better spent. So it persists, a monument to sunk cost and organizational inertia.

⁹ This number is staggering enough on its own but consider: you'll replace more cells reading this essay than attended your high school. Your body is running a population replacement program faster than most cities grow. And it's doing this while you're sitting here reading about coffee mugs and career choices. Multitasking at the cellular level.

¹⁰ Ship of Theseus thought experiment but make it personal development content. If you replace all the cells, are you still you? Philosophy majors have been arguing about this for centuries. Your body just shrugs and keeps replacing things. Be more your body. Less philosophy major.

¹¹ Actually, plenty of people want to ask this question. Career coaches make entire practices out of it. The problem isn't that nobody wants to ask. The problem is nobody wants to hear the answer. Asking is easy. Acting on the answer requires admitting you've been carrying around seven-dollar coffee mugs disguised as career choices.

¹² Actually, the entire self-help industrial complex tells you this. Constantly. "Let go." "Release." "Declutter." "Minimize." We've got Marie Kondo for objects and therapy for trauma and productivity systems for commitments. The message is everywhere. But knowing and doing remain separated by an ocean of cognitive bias. Hence this essay. Hence all essays.

¹³ Notice how we do this at networking events. "I'm a Senior Product Manager" or "I'm a software engineer" or "I'm a consultant." We lead with the role, the title, the thing we currently do for money. Not "I'm someone who thinks deeply about system design" or "I'm curious about how organizations make decisions." We've fused identity with occupation so thoroughly we can't imagine introducing ourselves any other way. Try it sometime. Watch people's faces when you skip the job title.

¹⁴ Different mug. The irony of keeping any coffee mug after writing this entire essay is the point. We're not trying to achieve perfect non-attachment. We're not Buddhist monks. We're just trying to notice when we're valuing something because we own it rather than because it serves us. Sometimes the mug serves us. Sometimes it's just taking up space. The trick is knowing which is which.