Once in the waiting room of the ER there was a girl with hair dyed grey and very distinct facial features, her very protruding and sharp cheekbones in particular, sitting opposite to me. Not attracted but intrigued by her looks, I glanced over at her more times than what was probably polite. The doctor called my name and I left the room, thinking nothing more of it.
Just a few days later, I was waiting for the subway at the station, and a girl walks past me. Her looks immediately recall the memory of the girl in the ER, but a few seconds of inspection determines it's definitely not her. The subway arrives 30 seconds later or so, and when the doors open the ER girl with the grey hair and cheekbones comes out of the train car that had stopped just in front of me. This was definitely her, as I not only recognize her peculiar face, but also the coat and necklace she was wearing.
This is probably the biggest moment of synchronicity I've experienced. Thought it was funny how coincidence brought the memory of a distinguished stranger to mind, and then a short moment later she appears just like that.
Another moment of synchronicity also happened at the subway. There's a band called Radio Birdman, who took their name from a misheard lyric from the song 1970 by The Stooges, which goes "Radio burning, up above". I was listening to that song as I was walking up a flight of stairs, and just as that lyric was sung, I saw a Radio Birdman concert poster on the wall.
I don't attach much meaning to these moments, even if it's nice to sometimes have a small counterweight to a rigorously materialistic mindset.