I once even thought I had seen my late grandmother. Can science explain my overfamiliarity with strange faces?

When I was in my mid-20s, I spotted my grandma through the window of a coffee shop. I was dumbstruck – she had passed away the year before. I stared for a moment, then reminded myself it couldn’t be her.

I’d had similar experiences all my life. Every now and then, I “recognized” someone I didn’t know. Sometimes I could quickly pinpoint who the stranger reminded me of – like my grandma. Other times, a face simply had a vague familiarity I couldn’t place.