Actually I don’t have any hobby understood as collecting things. But I know people who collect all kinds of things. A workmate of mine collects lottery, “do not disturb” cards, etc. I believe he has a room full up of his collections.
My brother used to collect stamps, coins, banknotes and a thing that I don’t know the name in English: it’s a paper that surrounds the cigars (“vitola” in Spanish). It’s because my aunt had a tobacconist’s. But after my brother’s death, nobody continues his collections.