Many people need to be pushed, and pushing them really is exactly the right thing to do. There is an occasional rare instance when it's not the right thing to do, hence this note to myself:
10. Beware of the boy who cries wolf. You'll end up pushing him hard. The trainer always tries to find balance on the question of "more intensity" and "more caution". The boy who cries wolf will cause you to err on the side of too much intensity. Let him cry wolf, and let him undertrain. Do not try to be a better conscience for him than he is equipped with. It is in the nature of things that you cannot make a student into a better person than he has the potential to make himself to be, this is an appropriate humility teachers must learn.
Obviously I have someone specific in mind. I think I may just ask him in the future, "Boy, do you think this is the kind of pain you want to be able to push through, or is it the kind of pain that means you've exceeded your limits?" I think this should work as an invitation to decide his own level of success.