Watch Reefer Madness. Better yet, talk to some of your local pot smoking wastrels. A short (say, 2min) conversation should be enough for any sane person to establish that they don't want to become like them.
(although I'm doubtful you want to take an objective look at the subject) I recommend reading a book called Weed the People.
Yes, I need to research pot and potheads immediately. I have to put that molecular dynamics kinetic theory project on the side for now.