The other night I ran into someone I met a few years ago at summer camp. I was staff and this person was a camper, and over the course of the summer we probably had a few (relatively uneventful) conversations. Upon running into this person, I said hello and it became obvious that he clearly had no recollection of who I was. I prompted him with my name and my role at camp and was met with a continued blank stare. Realizing I had just created an uncomfortable situation, I tried to downplay it ("its okay.. there were a lot of people there that summer.. and it was quite a while ago...").
This isn't the first time this scenario has happened to me... as in, I remember who someone is and they clearly have no idea who I am (and make me feel quite awkward in the process). Of course, the opposite has happened as well, someone comes up to me and knows all sorts of information about me and I have no clue who on earth they are or from what part of my life I should recognize them. But in those situations, if the person is trying to prompt me, I will at least
pretend to recognize them, even if it's in a sort of vague "yeah.. you kinda look familiar but I just can't place it" way. Sometimes it has later clicked in my head as to who they are but other times it remains as a blank.
Given it can make people feel lousy on occasion, I would ask.. why not pretend (at least in a vague way) that you know who the apparently random stranger standing in front of you is? While I wouldn't encourage flat out lying ("Oh! Of course I remember you!"), I'd say unless you foresee bad things happening (e.g. person is claiming to be your one night stand from last new year's and the conversation is occurring in front of your long time significant other)...
why not fake it?