Its an epidemic... It's awful, and yes you are correct. Everyone in that situation has the ability to break the cycle and never experiment with drugs. The issue is, most of us go through this stage when we are coming of age where we think we are invincible and that is when the disease takes ahold of the person with the genetic makeup needed for addiction. I know if I were in those shoes, I would probably be a junkie myself. My parents told me to never smoke pot. Guess what I did? Smoked pot. My parents told me drinking was bad... guess who got drunk? My parents told me harder drugs were awful. Guess who dosed as a teenager and climbed trees without ever physically touching a branch. My parents also told me speeding was against the law. Guess who got caught drag racing doing 127 on Kingston Pike?
If we all learned from other's mistakes or other's foresight, the world would be a much different place. Living in a world of ideals sounds amazing, but it's just not the way we work. Unfortunately, most of us only learn by our own experience and think we are not like the people who try to warn us. I know that was the case with me. My wife graduated HS with over a 4.0 GPA. She had a full ride to Vandy, Stanford, Yale, etc. She was 2 semesters away from a hell of a nice degree at UT because she wanted to stay close to home. She blew it all, and I seriously doubt it is really what she wanted from life...