You were listening to that whole video?

When watching youtube videos while your roommate is doing homework, make sure your head phones are plugged all the way in. Otherwise a few minutes into watching an alligator video she'll say "you know your headphones aren't plugged in, right?" Then you'll notice they are only plugged part of the way in. Sound was still coming out of the computer. And you might feel like an idiot.

Don't offer to be the "attacker" in a self defense class your roommate is teaching. You might actually get hurt.

When dying your hair pink so you can dress up as Tonks for the Harry Potter movie premier, make sure to get the front of your hair pink before the hair dye runs out. Otherwise when people look at you from the front they won't be able to see the pink. 

When going to a cabin for the night make sure you bring a blanket that will actually keep you warm in the 50 degree basement all night. Even wearing the one piece snow suit you found in the closet to bed won't keep you warm.

When going to a cabin with a bunch of girls, dressing up in the one-piece snow suit you found in the closet and then going on adventures in the huge cabin is always a good idea.