Here’s a fun riddle I remembered from years ago (thanks to cut-the-knot.org for help with the proper wording):
A man was looking at a portrait. Someone asked him, “Whose picture are you looking at?”
He replied: “Brothers and sisters I have none, but this man’s father is my father’s son.”
Whose picture was the man looking at?
I’ll post the answer below in a day or two.
Update: please see the comments below for clue & answer.