WoW taught me people are assholes and could they get away with it would kill you without a 2nd thought, come to think of it, MW2 also taught me this..
I learned if your names shepard your probably a bad guy, a lone Scientist CAN kill a entire army unit, and 8 zombies can be found in a single bathroom all thanks to valve
In all seriousness there was a question on my GCSE paper about red shift, the question was basically describing red shift,then asked if what they just described was red shift,blue shift or green shift, and i didn't know,so i guessed blue shift, cos it was a physics paper, half life is a physics term, it was a long shot but it was obviously wrong.. thanks valve!