Anyone else have big problems with finishing games?

[Cronos]

I love gaming, but not so long ago I realised, that from all the games i've ever played, I've completed just a few. I would love to start with series like The Witcher, or Legend of Zelda, but I'm 100% sure that I'll give up on those games after a few hours of playing. I've tried New Vegas and I LOVED it, but after a few hours I got tired and stopped playing, same thing with KOTOR. Anyone else have this problem?

I think it's a psychological problem, and in addition it depends on the game if it intrigues the player.
you can try to vary the games, if you play on an rpg give it 3 hours or 4 hours only and then play on a fighting game or beat them all or a sports game