From what I know, I think it must take a lot of willpower...I have never smoked, so it is easy. A friend of mine used to smoke at the back of the bike sheds at school when she was 13. She gave it up when she became pregnant with her first child. He is now 33 and she says that she still has the desire to 'have a smoke' every now and again. So I think it must be tough. All the best with your attempts.