motivation

there really is such a thing as "senioritis." why is it that when you've created some momentum toward your goals that you start to regress? it seems to be some sort of psychological battle within oneself, something self-destructive. and many, many people possess self-destuctive qualities. i wonder if it's a product of the modern age or if there's some sort of natural force that makes people fear success, cause it would make sense that the only way to go from being up at the top is down.