I've just finished reading Blink, and that surprised me with some interesting stories about the power of the unconscious mind. Sometimes consciously thinking about something doesn't work as well as leaving your unconscious to get on with it. I think I might do well to heed Ap Dijksterhuis's advice in this New Scientist article 'Sleeping on it' best for complex decisions
“At some point in our evolution, we started to make decisions consciously, and we’re not very good at it. We should learn to let our unconscious handle the complicated things,”