I'm Captain John Yossarian, 256th squadron of the Army Air Corps, serving as a B-25 bombardier, stationed on the island of Pianosa (close to Elba) in Tuscany, Italy.
Thousands of people I haven't even met are trying to kill me. My commanding officers, General Dreedle, General Peckem, and Colonel Cathcart are all trying to kill me. It even seems like ex-PFC Wintergreen is trying to kill me.
Naturally, I realize that to keep flying these missions is an act of insanity. But here's the catch. If I attempt to get grounded because I'm insane, which I clearly am, I cannot be grounded because my concern for my own welfare indicates that I'm sane. A sane man cannot be grounded. That's Catch-22. It's all perfectly rational.