Hi, I'm Rain, and I almost never finish the games I start. Almost. Never.
Partly because I commit the sin of reading the wiki. I am a completionist and a normal-easy difficulty player because, well, I don't like zombies and demons, and I don't like the creepy soundtracks they play while I'm fighting them! Plus, if I have to take like 40 tries to kill a boss, I'm not entertained anymore. Which is another reason why I don't finish games! Particularly Final Fantasy type games. Lightning Returns? I got like 4 bosses to kill. Ain't doing that shit!
As for completionist shit; I use a wiki sometimes to make sure I don't miss something or that I can make the better choice. Not like there usually is one in a good game, I'd say. But then I realize how much shit I missed at the beginning of the game and how many mistakes I made and oh, how I wish I hadn't done that; and then I want to start over. But I'm lazy as shit, see, so I don't want to start from the top. I'd get bored. So eventually I get stressed and stop playing.
LR has that all wrapped up in one huge issue for me. Mostly because it's a timed game, but you have this ability to temporarily freeze time. So I would try and get entire areas of the game done in a matter of ingame days (I completed the first area in one in-game day), which involved LOTS of wiki reading and LOTS of planning. Somehow I managed to play through the entire game like that until I reached the end, but when it got to the point where I STOPPED reading the wiki and realized that one day left at the end of the game WASN'T enough to finish all the endgame stuff, I got stressed and had to go to an old save and that's when I stopped playing xD
And sometimes I just don't want to see the ending. Fable 3. Some people say they never felt any emotional tie to the characters but I'm a sucker for this shit. I didn't want to see Walter die! So I never finished it. Although the section of the game with the evil monster and all the black oozing shit creeped me the fuck out. This is why I don't play zombie games.