Duffers need a different set of mental game strategies than professionals and low-handicappers, but most golf psychology books are oriented to golf pros and scratch golfers because those are the people who pay for sports psychologists' advice. Some even say that recreational golfers don't need mental game strategies, just more lessons.
Recreational golfers can benefit greatly from an improved mental game if the strategies are tailored to their needs. Duffers want to optimize their performance, but they also just want to have an enjoyable round, even when their game is less than optimal. "Now That Shot Sucked!: Golf's Mental Game for Duffers" is written by a psychologist and recreational golfer for recreational golfers to improve their mental game, play better, and enjoy the game more.