When life gives you lemons, don’t make lemonade. Make life take the lemons back. Get mad! I don’t want your damn lemons, what am I supposed to do with these? Demand to see life’s manager! Make life rue the day it thought it could give Cave Johnson lemons! Do you know who I am? I’m the man who’s gonna burn your house down… with the lemons! I’m gonna get my engineers to invent a combustible lemon that burns your house down!

- Cave Johnson, Portal 2

Maybe not words to live by, but certainly a memorable quote.