I'm going back around 30 years now, but I had taken my two oldest children to Harrods to see Santa (in those days the experience was incredible with a grotto which was an experience on its own). I was standing in the queue, and the children playing with amazing toys (the elves encouraged this & helped children to play), about an hour in, I turned round, and unbelievably saw my sister, half an hour later and there was my Mum with one of her godchildren, after much sign language and message passing it was decided we would all meet for tea upstairs.
Anyway, at said time up I went with the by now exhausted children to the restaurant, and as I arrived who did we see leaving? My father with his wife and two children!
Dad lived in Bedfordshire, Mum in Oxfordshire, my sister in Hertfordshire and we lived in Devon. None of us had known that the other was coming. Now what was the likelihood that everyone would be there in Harrods on that day?
As an aside I went to visit Santa fifteen years later and what a disappointment, no real grotto magic, a real sense of commercialism, and half a dozen Santa's. Not the same and totally lacking any sense of mystery.