Have you read Bob Baer's "See No Evil" - it goes into a lot of details about his experiences being recruited and working in the CIA.
This is somewhat top of mind because I just found the typewritten letter (this was back in the early 90s) spelling out the process of getting to the interview. With OCS the process was obviously way more explicit, but this was a series of phone conversations that ended with that letter and plane tickets at the airport on a certain day. I was newly married with a baby on the way and chickened out.
While I definitely regret not following through, I really can't complain as I've been very fortunate since.