Back in the early days, I was a purist madman. Nintendo, Sega, Commodore, Playstations, PC, etc... I played all the games and I finished them, preferably with 100% completion. It's the opposite now, I still love games, and it's a love which will never fade, but I just play them for a quick fun, and I only have a few hours to play every week anyways.
I start something and I play it for a few minutes or hours and I drop it... perhaps I play it again a few days or weeks later, but perhaps I won't, or maybe I spend an afternoon with it and I finish it in one sitting... It's a lot different when you are grown up (and when you spend a whole day in the server room for example), you are not always in the mood to sit down to the computer at home too, so I don't care about it that much anymore ... I think I only have like 5-6 perfect games on Steam for example and probably I have the same amount on GOG or Origin too. I'm sure I finished a lot more but I bet it's still not more then 40% combined
(Edit: Steam says 32% out of 456 games but that's weird because there are a lot of games I know I finished for sure and never got the achievement for it and maybe the free weekend games bring that ratio down too perhaps?)...