All the time
It happened once, it was embarrassing and I felt terrible when I remembered who it was afterwards.
Well, she said she knew me.
She actually didn't.
Once close enough, grabbed my wallet from my back pocket, pulled out the cash, threw the wallet and ran.
I have... Well... Half kind of face-blindness. I can't remember faces that well. It has been bothering me for a long time. Sometimes people come up and start chatting with me, since I'm apparently more or less a famous figure in my home town, but... I just can't seem to remember them.
Hasn't happened in a restaurant but some former charges have seen me through the checkout!
Sounds like a reunion at the in-laws to me.
A couple of times. I can remember most people, but not their names or where I knew them from.