a) make it abundantly clear that sometimes, what Daddy says, goes, and
b) realizing that kids behavior fluctuates up and down with their energy level and environment. Trying to rationalize with a kid who didn't eat lunch, or who's wasted at the end of the day is a lost cause and you just have to step up and enforce.
I promised myself when I was a child that I would never tell my children, "because I said so." You know, sometimes it really is "you just have to put up with it and do what I say...because I'm Daddy, and I said so."
Dad: Go to bed, please.
Kid: Why?
Dad: Because I said so.
post hysterics...
Dad: Why do you think Dad was telling you to go to sleep?
Kid: I don't know.
Dad: Well, what are you doing today?
Kid: Going to school.
Dad: And if you don't sleep before you go to school, what happens... etc etc.
Of course this is variable on the child, the issue and the level of understanding. I've done this though and while it doesn't solve the immediate concern, it sure as hell helps with any possible recurrence.
You're not interested in teaching them to justify poor judgement, you're trying to teach them the judgement skills directly.
Of course, situations vary.