The OP's situation was way over the top, obviously. Most of the discussion here has been about what you should do if you meet the party of the second part while out in public -- which is a reasonable topic for discussion, and it does not take away from recognizing the OP's trauma.
My problem is that I am so bad at remembering people after only one or two meetings. I once met one of my own clients at Niagara Falls. In comapny with respective SO's. Definitely couldn't remember her name. And while I knew I had seen her the previous day, at that moment I couldn't remember who she was, nor where I had seen her. Was I her client, or was she mine? Tricky if you get it wrong! Fortunately, she couldn't remember who I was, either. We smiled half-heartedly at each other -- just in case -- and got the hell out of there.