Mmm. That does remind me of the quite nice social interaction some types of collecting gives. For example, a neighbour was a thimble collector so whenever visiting somewhere, we would look for a thimble. It gave us some entertainment as a tourist, like a treasure hunt, and then the nice moment to give it to the neighbour and show we were thinking of them while away.
It can go wrong though. I've known a few friends who have become associated with "a thing" because their family saw they owned one of "the thing" and now it's the exclusive theme of all presents but they don't have the heart to correct them and reveal all their presents were unwanted!