I had a friend once. He had a cactus. The same cactus sitting on his windowsill for fifteen years. Then one day someone gave him a second cactus. And within six months he had to move to a bigger house with enough space for his cactus collection.
Detectorists is a BBC television show about metal detecting, and by extension, hobbies in general. (The first season is on Netflix and I highly recommend it.) This quote is from a scene that wraps up the final episode of the first season. The two main characters are discussing their hobby, and the parallels apply to any kind of collecting as well.
Why do you have five versions of “Iron Man” if it’s all the same movie? Why do you own movies you’ve never seen? Or don’t even like? Why do you buy the steelbook when the plastic case is less than half the cost? Why must you own imported versions and limited editions when you could run down to the local store and get the same movie – in some cases with the exact same disc inside?
Because you are a collector.
And whether it’s baseball cards, coins, comic books, Blu-ray steelbooks, or cacti, you’ll always be collecting. You don’t have to explain it; it’s part of who you are. So enjoy every single piece you add to your collection—whatever it may be.