Final Fantasy VIII and IX. Played both a lot and enjoyed them even, but still didn't finish them. I don't know, suddenly I just lost the motivation. I only finished both years later. I can't explain that myself, either.
I've experienced that too. It's a weird feeling, knowing you're like at the very end of the game but can't push yourself to finish them. I know I've literally loaded save files in RPGs year later after leaving them, only to play them for 20 minutes, beat the final boss and then actually be done with the game. I can't give an explanation either, other than maybe getting like very burned from the game and it unfortunately hits at the very end?