excerpt from the Saria dictionary:

[sagesaria]

Awkward: meeting somebody who went to your high school and knows you by face while you don't recognise him at all.

Comments

[rinichan.livejournal.com]

Diagnosis: You are/were a theater geek. :)

(btw, if you find the performing arts department or a drama teacher, you should be able to find out if there's any interesting theater stuff going on!)

[sagesaria.livejournal.com]

I'm probably gonna take Theatre next semester :D

[maugorn.livejournal.com]

This exact thing happens to entertainers alot.
You were, after all, a highlight of the annual talent show.

If you continue to entertain, you'll have to get used to this phenomenon.

If they are somebody you should know, try to use your "Con-Fu" to see if you can get them to speak their name. If that doesn't work, politely fessing up is sometimes disappointing, but at least it's honest.

Make sure you always tell them that you're glad they remember you, and that you will do your best to remember them next time.