"Yeah, my dad knows, but he doesn't tell me not to because he smokes and he doesn't want to be a hypocrite."
My jaw dropped at this and I had no idea what to say. Since then, I've had dozens of conversations with students and parents that ended similarly:
"I can't tell my son/daughter/athlete not to use drugs, because I did them when I was young..."
"It's tough to tell Johnny not to smoke, when I smoke too!"
Okay, here's the point - please print it out if necessary:
It doesn't matter what you did when you were young and dumb, you have a responsibility to the children in your charge to tell them "no" to the things destructive to their health and growth. If it bothers your conscience, GET OVER IT! ...and if you smoke or do drugs, isn't it time you stopped?
I already have this conversation planned for my son if it ever comes to that. It will go like this:
Son: Dad, did you do drugs when you were my age?
Father: If I say 'yes', you will use that against me and argue 'See Dad, you turned out okay and so will I.' and if I say 'no', you will say 'Well, times are different now', or 'But, you were a nerd.', or 'How could you understand if you've never done them!?'
So son, here's the deal - if you smoke or do drugs while living under my roof, I will kick your ass. If, after the initial ass-kicking, you do them again, I will hit you on the top of the head so hard that you will have to unbutton your shirt to do bong hits. I love you.