Honk if this has happened to you:
You meet someone, maybe at a party or a conference, and have a wonderful, interesting, thought-provoking conversation with them. They are brilliant, they are fun, they are witty-- they think you are brilliant and fun and witty. You think this is the start of a beautiful friendship.
Then you see them the next day, and they smile and wave, and you smile and wave too! And then you realize they were waving at the person behind you, and they didn't even see you. But they see you now, because you are smiling and waving like an idiot and... they can't place you. They tilt their head and furrow their brow as they pass, unable to remember why you look familiar, if indeed you even do.
Luckily for me, right after this true-story, a guy passed me and smiled and waved! And I had no idea who he was. But I smiled and waved back, and even tossed in a "hey" as I passed. I didn't want him to know the difference, even if I was "heying" at the guy behind him...
Life is... cyclical.