acronym for "Post Relationship Disbelief," when one reflects upon past relationships and cannot believe that:
1) they lasted for as long as they did,
2) that they ever began at all, or
3) any variation upon this theme.
Girl: "Wow, do you remember when I dated that pompous asshole? Oh, and that other pompous druggie? And that guy who did nothing but lie to me?"
Friend: "I take it you're having some serious PRD."