I work in a hospital. Where hallways intersect, they have semispherical
mirrors, so people, stretchers, and other
assorted equipment, don't run into other people, stretchers, and assorted equipment.
I was walking down the hall one day, nobody else was around, and I looked into the mirror. For whatever reason, I thought I was looking at the intersecting hallway, and I saw someone walking closer. "Who is that?" I asked myself. "Eric? No..." I reached the intersection of the hallways, and nobody was there. I was confused. I hadn't recognized myself in the mirror.
Regularly, I wouldn't write-up such stupidity, except that it's happened every day since then. At some point, I'll glance into a mirror, and see a stranger. He looks like me, he mirrors my actions, but the recognition of "self" does not come.