Here's the rub. College players are "kids", usual 18-22. Or, in BYU's case, 18-25. But, it still holds true in the context of every game is big, even the FCS/G5 games. The players may not get that, but the coaches do...or they should. If you, as a coach, don't take the necessary steps to get your players up for a game, you should go find a different job.
BYU has played three games this year in which the team was unprepared mentally: Oregon, Wyoming, Utah State. In two of them, BYU had the talent to overcome. Against Oregon, BYU got boat-raced. The common denominator in all three was that KS said "I didn't prepare the guys mentally". BS. Do it or find another job.