I'm familiar with the story from reading essays on it and such, but as I read it I got the distinct feeling I knew it. Not just from an essay, but something more. However, I didn't know every little bit.
I wonder if I read an abridged version of it a long time ago and didn't remember doing it, or something.
Either way, anyone who hasn't read it, definitely should. Especially with some of the recent happenings of late, with regards to school "security" and stuff.
After reading it, I find myself with a really strong urge to seek out and re-read A Canticle for Leibowitz, which I last read about 8 years ago.