I have a bunch of them, mostly stuff from particularly nostalgic periods in my life. I get sentimental so easily haha. I still have this really old fleecy coat I've had since I started school. I'd never give it up even though it's not my style anymore as I mostly wear puffer coats now
One time I found the most circular rock I'd ever seen. About 2.5" wide, 1/2" thick, smoothly worn by the ocean. It was a pale gray rock with dark speckled pits. It was like a cartoon moon. I took it from the beach, intending to keep it as a souvenir of the trip. It never made it. It was accidentally thrown out in the chaos of leaving a hotel.
I stole that rock from it's ocean view home and sent it to a landfill. It was just a rock and it tears me up unnecessarily.