What’s the most random item you’ve kept for sentimental reasons?

I kept a sachet of artificial sweetener given to me randomly one afternoon by a friend I had a crush on. Neither of us used the stuff, we were just being silly.

I had it for a couple of years and kinda forgot about it, then the friend killed themself and it became unthinkable to get rid of it. Maybe a decade later I could finally bring myself to see it as just a pack of stale chemicals and throw it out.