Not in the mood

Yesterday I played a game when I didn't really feel like playing. I played it just to keep up with the training. Did horribly as expected. Dan H. says to play only when you are in the mood and have some energy. Now I know why.

Early in the opening my 1500 opponent left book in the Vienna Game. I had forgotten all of the book moves but through analysis found the correct ones anyway. He dropped a Knight but on my next move I gave it back with interest and allowed a King side attack. Then I let him fork my King and Queen twice. It was a disaster. Throughout the whole game it made me realize how much my thought process has been aiding me and when I neglect to do it how terribly I play. The funny thing is I was taking the same amount of time per move that I usually do but I wasn't "seeing" things like normal. I would stare at the position and say, "Why did he make that move?" and I would come up with the completely wrong answer. They were all one move threats too.