Oli (5) and I were putting together a jigsaw type puzzle from a cracker - a dinosaur in 5 interlocking segments.
I picked up an end piece and said "Here, this is the head, isn't it". It looked like the head of the Loch Ness monster in That Photo.
"No", said Oli, "that's the tail".
"No, I think that's the head, and look, that's the tail end".
"No, I'm the expert, you don't know anything about dinosaurs"
And you know what?
He was right. It was a Stegosaurus, and the long bit with the bumpy end was the tail, and the piece with the shorter pointy protrusion was the head end.
He knew this for two reasons. 1) He is indeed expert on dinosaurs and 2) He had the piece of paper that came with the puzzle with the key on it, that I didn't realise existed.