I'll let you into a little secret.... when I was young and immature me and my friends used to drive past random strangers and honk and wave at them... for no other reason than to make them wonder if they knew us. So it doesn't necessarily mean anything unpleasant or personal.
So did we
How silly is youth.
Now I am a bit older
I have been known to mistake complete strangers for someone I once met.
Yesterday, on a local walk, I met the parents of a child my daughter was at primary with. Recognition meant we greeted each other like long lost friends, asked all the right questions- how were the family?, grandchildren? still living locally? etc. Fifteen minutes of cheerful chat later we went on our separate ways. I can't remember their or their children's names, I am sure they couldn't remember mine and my daughter was never friends with theirs nor I with them. Funny world.