I was... 19? Almost 20? I do it rarely, as in, the last time my sister's fiance made brownies and I had one, that was about 3 or 4 weeks ago, and before that was Thanksgiving with my boyfriend and his best friend, and before that was in June... I never did it before because I was on the college tennis team and you get random drug tests and how bad is it to let your whole team down and get kicked off... it'd be extremely lame.