I find that most people in my life have at least one "thing" they are collecting. It is often an insight into their personality and it is fun to hear people talk about something they are passionate about.
I collect magnets of places I’ve visited. I have two collections: one is upstairs on a magnetic chalkboard and it’s only amusement parks (along with my scratch-off map of parks) and the other is downstairs on the fridge and it’s a random mix of cities, states, countries, and attractions.