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 vintage computers. I have a bunch of laptops from 2000 and earlier, as well as an Atari 800xl, an emachine, and a ti 99/4a. The reason I started was because when I started studying computer science, I fell in love with the history of computing