I had a comic collection as a kid, it all got tossed in a move in 1963. Some of them would now be worth some money, except they weren't in very good condition. About the time we moved I went nuts building plastic model kits. Those all disappeared a few years later. I still have most of the science fiction collection that really got going in the late '60's.
In the last five years I've started collecting models again. Unlike the earlier collection they are all ships and all the same scale: 1/700. Today's models are vastly more detailed than what I used to do. I currently have two battleships, two aircraft carriers, a submarine, a destroyer and the Titanic. I'm putting the finishing touches on one of he aircraft carriers and eyeing my next project, probably another battleship.
Am I nuts? Probably, but I like doing it, I stay within a budget and it doesn't hurt anybody.