We've had similar topics in the past, and I was going to respond to this one in a similar fashion - getting rid of the PS1 games i owned from new, many of which I have yet to replace. But, for some reason, I got thinking about this and a few things running a lot deeper popped out.
I regret having overestimated my free time since I started collecting again properly @ 10ish years ago now. I've gotten good at trading for stuff, picking stuff up when it was cheap etc., but I've ended up with a bloated collection containing stuff I wouldn't want to play even if I did have the time, I've had to invest one hell of a lot of time trimming it down to where it is now and re-arranging my 'actual' collection. That's time I would have rather spent elsewhere. At least my collection is now a collection of things I want to play or keep, not just things.
The other thing, which has sort of been at the back of my mind for some time, but crystallized when I was thinking about this topic, is that I've been picking up fishing and flight sim games for the past 10ish years with the intention of playing them with my Dad or at least setting them up for him to have a go on. I've moved out, have a long-term partner and a baby on the way, my Dad's nearly 70, it's just not going to happen. In a way that's regret, right there, but the thought of browsing through these games in the future after my father passes away and getting smacked in the chest by it.. well that stung. Subconsciously that must have been there awhile, but when realization really dawned I pulled the 360 flight sim games (Ace Combat aside) out of my collection as quick as a flash, either yesterday or the day before. Certainly don't need something like that staring me in the face somewhere down the line. I'll be going through the fishing games and flight games on other systems very soon.
Between the two I'm feeling a lot happier with my collection and have also got rid of something that was at the back of my mind, so thanks for the topic GF78!