Also, lock your door when you sleep. I remember one night when my roommate was away for the weekend I woke up to someone entering my room at about 5 in the morning. Took a year off my life to turn around and open your eyes to a tall, muscular guy making his way to your bed.
(Sprang out of bed and told him to “get the [expletive] out of my room”, and he did–but I’m a pretty tall guy who lifts. He was just a drunk, confused teen who didn’t mean any harm; but I now lock my door whenever I go to sleep. My laptop, cell phone, and wallet were all exposed on my desk.)