I’d say you’re definitely overthinking it. I’ll look at the high end achievements if I’ve finished a game I like, as that could point me towards things I may have missed during my initial playthrough, but other than that, I don’t think about them at all.

If I actually do 100% a major game (Like I did for Fallout New Vegas) I’m proud to have accomplished it, but I’m not losing sleep over the other 3000 unfinished titles I’ve played.