I spent all afternoon walking along the waterfront. At one point, this pair of tall young women were walking along the same route I was. We were both stopping to look at the sound, or down at the sea stars in the surf, and so we'd overtake each other from time to time. At one point, as they overtook me, I heard the blond one say to her brunette friend, "I mean, I like cheese, but I don't understand why *you* like cheese."
I almost said something at that point, but I'm pretty sure they'd noticed me, and it seemed weird.