I second this. His books have been a great help. I feel the mental side of my game has improved over the last year. I used to have a bad hole and that would affect the rest of the round. On most occasions I can now put them to the back of my mind and get the round back on track.
Comp not so long ago I had a 9 and an 8 after going along OK. I then managed to go par, par, par, bogey and double bogey to finish my round off and play to my handicap for the first time in a comp. Previously I would have let it get to me and messed up the whole round.