They have those commercials because some people are pussies and blame thier problems on other people. "I really didn't want to do it, I was pressured to. I couldn't help it" = bullshit. What happens is kids get busted by parents, teachers, etc.. and instead of being repsonsible for what they did, they pass the blame on to someone else. I'm sure that there are legitimate cases where someone was pressured by a friend and did something they didn't want to do, but for every 1 real case, there's 20 fake ones.
Even after you grow up, peer pressure is around in some form. People grow up, get jobs, and then get a car, house and anything else that their buddy has so they don't feel like a looser.