Hypocrisy and being a Parent

Why is it that some people can't draw a line between being a kid and being an adult?

Some parents of former students (I have heard) allow their kids to do drugs. They find bags of marijuana and give it back, and even buy legal but addictive drugs for their kids to...I don't know, play with? Some adults who shall remain nameless have giggling confessed that their kids have found their "stash." Excuse me? Are you a grownup or a boneheaded college student?

I heard an interview on NPR today where the interviewer asked the guest how she could talk to her 15-year-old daughter about sex without feeling like a hypocrite, given that the guest had become sexually active at 14? I wanted to scream (with credit to Lindsay Bayles, a teacher at my school whose basic idea this is): You are not a hypocrite for telling your daughter not to make your mistake! Be a grownup! Admit you MADE A MISTAKE as a 14-year-old! 14-year-olds are stupid by definition! It's okay!

Or: Learn from the mistakes of others. You can't make them ALL yourself.