That overwhelming emptiness you feel upon completion of any of the Half-Life games.
Man, I just finished Half-Life 2 and now I have nothing to do. I feel so empty. I think I'm going through a Half-Life crisis.
One has a half-life crisis the night before a large project or a big test is coming up the next day in ones Chemistry class.
Man, I'm stupid! Why did I ever take AP Chemistry? I've already exposed myself to 7 different types of radiation, and this project is due before I can go in for treatment! Pretty soon, I won't have a half-life crisis, I'll have a no-life crisis!