I was just browsing someone elses site, and came across this:

I recall, when I was at school, a conversation between a teacher and a pupil which went something like this:

Teacher: Why did you do [whatever the trivial misdemeanor was]?
Pupil: Because [random other pupil] told me to!
Teacher: That's no excuse. Would you jump off a cliff if [random other pupil] told you to?
Pupil: No.

The learning experience here is clearly that you should always think before doing anything rather than blindly following order. The thing which piqued my curiosity was another exchange later the same day between the same teacher and pupil:

Teacher: Do [some mundane vaguely learning oriented activity]
Pupil: Why?
Teacher: Because I said so.

It's hardly surprising psychiatry is such growth industry really...