And I'll counter with reasons why I do regret the experience:
The multitude of ways I felt awkward in school, and later, in the workplace.
The money it cost me by not being able to pursue higher education sooner, and not investing in a 401k earlier because the world was ending soon.
It hurt my relationships with the opposite sex because of the strange expectations and hangups the WT instilled in me.
I'm just getting warmed up here. Someone else want to add to the list? Don't let me hog it.