The greed for more material.
Yesterday I finished a pretty good game of chess, which could worked out different for both player a few time.
The main thing twisting the game all the time was our greed to get more material made us forget about looking at the strategical, long-term, game.
As you can see in the comments, things going through my heads, motivation for some moves, and lack of thought put in to a move.
Anyone who had the same problem?