My favorite is about my son. About when he was 3 or 4 I am stepping out of the shower and he comes running into the bathroom, beaming a huge smile and pointing at my junk.

Excitedly he exclaimed, "Daddy! Your penis is circus sized!"

I paused for just a moment and said to him, I think you mean 'circumsized'.

He became suddenly deflated, said 'oh...' and sulked out of the room. Later I mentioned it to my wife, and she explained they had a talk the other day and she tried to explain how he and I were 'different' down there.

So he must have misheard, but what strikes me as funny was his delight at the idea of making fun of my circus sized penis, which he obviously did not have.