"Guess who?" I said.
She turned around. It wasn't the person I thought it was. I was mortified. I ran around the corner to the next aisle, then the next and the next.
A few minutes later, I heard her telling a friend about what I did. When they came around the corner of the aisle I was in, she pointed at me and cried out, "That's her!"
I was even more mortified. I ran out of the store.
For a long time, I considered this one of my most embarrassing moments. I think that's actually the funniest part of the story.