The great mistake is to anticipate the outcome of the engagement; you ought not to be thinking of whether it ends in victory or defeat. Let nature take its course, and your tools will strike at the right moment.
If the world were merely seductive, that would be easy. If it were merely challenging, that would be no problem. But I arise in the morning torn between a desire to improve the world and a desire to enjoy the world. This makes it hard to plan the day.