Let me talk a bit about the expression “catch-22.” Do you understand what a catch-22 is? This expression is so well known now that it has entered the American lexicon: well, a catch-22 is a situation that is unresolvable, one where there is no good choice, no best path to take.
In Heller’s novel, the catch-22 is a very specific catch in a very specific situation. The situation in which the protagonist found himself was that he wanted to get out of combat by declaring himself insane. So you see that in this situation there was a very specific catch. In American culture now, though, this expression is used more generally. It refers to any situation where there’s a catch, where there’s no solution, where there’s no way out.
One more bit of information about the expression “catch-22,” about the number 22 in the expression. This number doesn’t have any real meaning; it just signifies one in a long line of catches. Heller really could have used any number; it didn’t have to be 22. When Heller was first writing the book, he used the number 14; the book was originally titled Catch-14. Then, in the production process, the number was changed to 18, so the title was Catch-18. But then there was a problem with the number 18 because there was another book with 18 in the title, so Heller’s title became Catch-22.