OK, so SWIM has never taken LSD but will probably try it soon. He was very jacked and couldn't wait to hit it, but then he spoke to his friend who scared the bejeesus out of him about bad trips. This is his worry:
SWIM recently saw the Exorcist. While the movie really doesn't bother him too much, he is worried that when he trips, he will experience the movies phenomenon because it is fresh on his mind. Maybe LSD does not work that way, but he doesn't know, and the idea of seeing terrible zombies and shit walking around is indeed a very scary idea.
SWIM would like to know what exactly a "bad trip" entails, if a person can get you out of it, how likely a bad trip is, and most importantly, if this "exorcist" thing is at all plausible.