Did You Know Where “Catch 22” Comes From?

Ok people- let’s hope I can get back into the swing of things and post once a day again. Here’s my first post this week and the beginning of my attempt to get back into routine:
I chose an origin for this week that is quite widely used- and it surprised me when I saw where it came from originally! The one I chose is “catch-22” which usually refers to an impossible problem in which the solution effectively cancels itself out (although often misused to mean any difficult problem). This originally came from Joseph Heller’s book of the same title about a reluctant American wartime pilot for whom the only living alternative to continuing in service was to be certified mad; the ‘catch-22’ was that the act of applying for certification was deemed to be the act of a perfectly sane man. I’m still a little unsure as to whether the author made up this phrase or what, so if you know- let me know- but it’s interesting nonetheless. Maybe the military form to complete for certified madness was #22 or something.