Collections add a little something real to an interest. You are into baseball? Collect baseball cards and baseball memorabilia. Some find a tactile connection improves their enjoyment. For some people, it may be old video games, for others it may be coins, stamps, achievements in video games. Yes they are digital, but you can see them in your achievement/trophy list. I think some people are drawn to collections more than others because they favor a certain learning style over another. I'm not educated in behavior in any way so I am qualified to share my opinion on the Internet. There's nothing abnormal about that. The collecting part. Not the part where I have no real knowledge on a topic but I feel my opinion is worthy of being heard. That's actually normal, too, probably. But it shouldn't be.