Gum
Sometimes I need to ensure the quality of my breath, so I reach for a stick of gum. However, I don't always have my gum on me. Often, I forget it at home, or at work, or in a jacket.
So I bought 5 packs of gum that I distributed to my house, my work, my backpack, and my jacket.
Charger
I like to co-work outside my house, which entails bringing my computer there. Unfortunately, my computer's battery lasts at most 2 hours. Also, my home setup is somewhat intricate, so getting my charger into my backpack is a pain in the ass.
So I bought another charger, and put it in my backpack.
Conclusion
I had an ugh field around buying duplicate items, telling myself I should have the willpower or memory to make sure I have what I need when I need it. Giving myself permission to buy duplicate items has made life a little easier, and now I'm on the lookout for more places where I can apply this. Maybe I'll have multiple copies of a book in different places.
Shoes might be the one item that you can't do this for, but maybe I'm wrong.
Pre-covid, I bought a pair of shoes. But I am averse to throwing items away before they are properly "dead" (or until they really require effort), so shoes that still have some soles on them (and fit comfortably rather than the tight fit of new shoes) would still be used.
Because there were lockdowns and the like, I wore my shoes a lot less. I went out a lot less. My grocery store is rather close to my house. The new shoes spent two years in their shoe box.
Lockdowns were lifted and I started spending more time outdoors again. Within a month, my old shoes were deemed "properly dead", and I switched to the new shoes. But within two weeks, the leather on them started flaking off.
Maybe I bought poor quality shoes. Or maybe I didn't store my new shoes well. But I've got the feeling that shoes don't keep as well as most other clothing does, and that you won't get the full lifetime out of an old-new pair.