I have some of the same issues leftover from a childhood in which I was told I had to give 110%, every single time, on every assignment. It took me years to learn that most people - including my teachers - could not tell the difference between my 110% and my 75%, and that 75% is actually sustainable. Perpetuating this is one of the things I'm most worried about when I think about being a parent - not only because I will, inevitably, want my kids to be scholastically successful, but also because it's the sort of mistake parents don't realize they're making. They think of it as helping their kids reach their potential, especially in cases where their potential is high, and so they don't see the harm it might be doing longterm. I've mostly managed to escape it, but I don't think my younger sister (who was never quite as good as I was in school) ever has.