Similar, but also with Google's help: on the second date with my current girlfriend, we took a selfie. Google Photos then identified her face from a picture I had snapped five years previously... it turned out we had already met at a wedding, had a somewhat tipsy and flirtatious conversation, but since we then lived a long distance apart, and I was still disentangling myself from a previous relationship, I didn't make an attempt to follow up at the time, just left with a vague memory of "cute girl in city X, it would have been nice to get to know her under different circumstances." Now I live in city X and the circumstances are so much better :)