Yeah, it's funny - he also said that Beatrice sees pictures of him as a Beatle and says "that's daddy when he was different"...

It's fascinating, the way children express these things - they understand but it takes time till they learn to put it right. My 1 year old nephew's first word was "daddy" and he calls everyone daddy by now (all the men, that is...). It's so funny, my dad keeps trying to correct him - "No I'm not daddy, I'm grand-dad" (in Hebrew it's almost the same word, you see, so it's kind of confusing...), but when asked "Where's daddy" and "Where's grand-dad" he points at the right directions. I was shocked the other day to find out that he actually knows my name - he was asked "Where is Efrat" and he actually pointed at my direction. I can only imagine how confusing it must be for children of celebrities, to grasp that their "daddy" and that famous person is actually the same person.
I used to babysit a lot, you see, so I have plently of examples. A 3 year old boy I baby sat actually told my once - Hey, Efrat, You're mummy..." I just thought - "Oh god, thank goodness he mother isn't here...". There was a 2 year old boy I used to babysit, and his mother told me once that everytime some else babysits for him - even from his family - and they ask him "who looked after you today" he says "Efrat"... "Efrat" was just a different name for a babysitter, you see... yeah, it's a fascinating issue, not doubt...