Thinking straight

The mind is a strange thing. Focused and clear it can be razor sharp, but defocused and tired it is dull and unreliable. Recently I played a 'defocused' game. Made three major (read: stupid) errors, practically in a row. Pretty unbelievable, as after the first one you say to yourself that this is the one, and only one mistake you're gonna make in the whole game. And than, with astonishment, the second and third are made. It never happened to me before. Sometimes it is really difficult to keep thinking straight ... It was a true nightmare.