I keep anything that was a good memory. like movie tickets, sand from the beach, etc. I also collect coins. Well my dad did and i kept his collection. I dont know if he traveled to these places or just got them from other people. Coins all over the world, china, europe, etc. I looked up most of them and some are really old and worth money. But i wont sell them. the only thing i have to remember him. I want to continue collecting and give them to my kids if and when i have some.