When I run into former schoolmates of mine, I simply ignore them and act as if I don't know them, unless we were particularly close. Even university people (One of those came into our office a couple of days ago and saw me but I ignored her, but she recognized me and told people

).
I'm not even acting most of the time.

I bumped into a woman who worked with my family about 6-7 years ago. She came running over to me all "OMG I haven't seen you in ages, how have you been. OMG your kids are so big now, is that your daughter? wow I can remember when she was just a baby"..........and on and on, and I was so mortified because for the life of me I could not remember her at all.
I just stuttered blankly as my mind tried to piece together who the fuck she was, but nothing sprang to mind.

I apologised and admitted I didn't remember her. She took it kind of badly and walked off embarrassed.
Then when i left I sort of remembered her.

I'm not sure if this is a life saving technique that helps me avoid talking to people, or if this is terribly crippling right now.
^^ This sort of thing happens far too often. :/