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.
Carnaval Emblems! In the province of Noord-Brabant, Netherlands it is customary to decorate your carnaval coat or "boerenkiel" (farmer's coat?) with emblems from carnaval events or clubs.
I started because I completely fell in love with carnaval!
Below is an example of such a traditional "boerenkiel".