I have quite a few pairs of shoes, each at different points in their lifespan. In the messy pile just inside my door, my shoes line up in a way that makes them look like an extended family. The head of the family, so to speak, would be a pair of yellow shoes that someone less sentimental would’ve thrown away months ago. It’s not easy for me to get rid of shoes.

I’ll wear shoes until I’m just wearing socks. When confiding this in my friend, he confessed he also waits to throw his old shoes away, reluctant to remove them from the lineup. Aside from wearing them to exhaustion, he keeps them long after they serve any practical purpose.

I had a few ideas as to why shoes are harder to get rid of than other articles of clothing. Generally, we have fewer shoes than other articles of clothing. I go shoe shopping significantly less often than I go shopping for jackets or long-sleeve polos, for example. It could also be that shoes are the last thing to be put on and the first to be taken off. But I think the answer is a little less complicated and a lot more cliche. It involves the process of “wearing in” shoes: drawing familiarity from newness.

A shoe, once worn in, becomes personalized. It loses the uniformity it had when it was new, and it borrows the wearer’s personality. When we talk about “putting miles” on our shoes or any article of clothing, we mean going on adventures in them, embedding memories in the laces. I couldn’t figure out a sole-soul pun, but making one would not have overstated the double burden our shoes bear; our body weight and the weight of our memory.

It sounds sentimental, but I remember the best pair of shoes I ever had. I took a picture of them freshman year before I threw them out, well before I knew I’d be writing a column to commemorate them. My point is that most people can imagine their own favorite boot, shoe, or slipper. The timespan through which our favorite pieces of footwear carry us distinguishes them. It immortalizes them.

There comes an imperceptible moment when newness yields to familiarity, and attachment blossoms. Unfamiliarity becomes familiar but eventually must return to unfamiliarity. Until they’re worn in, shoes are both uncomfortable and foreign. Once they’re worn in, we literally share each step of our lives with them. Some shoes are comfortable when they’re brand new. These shoes have been harder to throw away.

Inevitably, we outlast and outgrow our shoes and we have to face whatever is so dreadful about getting a new pair. I think what’s so dreadful is our denial that a brand new pair of shoes can take us as far as the last pair did. New shoes have big shoes to fill if they want to live up to old shoes.

A similar phenomenon applies with new haircuts. I wondered why everyone puts off haircuts and how rarely people love their new haircut. It’s a change. Our hair grew with us between haircuts and we don’t want to erase something so personal. Longer hair is evidence that time has passed and that we’ve remained. It could also be that people want to look cleaned up and fresh, but I refuse to deny the profundity of our attachment to the familiar. Once shoes stop offering comfort in the sense of arch support, they start offering comfort in the sense of encasing memory and however many miles within.

This is my most important point: we live through the tug-of-war between the known and unknown. Shoes transition from new to worn to unwearable almost without us noticing, and it’s our instinct to keep them or wear them out as evidence of our perseverance. We never really outgrow our shoes, whether they end up thrown away or collecting dust at the bottom of a shoe pile. With every new pair of shoes, we admit to ourselves that there’s no conquering the unknown, but whether our shoes are threadbare or brand new, we continue to walk further into it.