QUESTION

I have a question… Your probably busy and I don’t know if you personally update this page but I am reading ‘Why God Is Laughing’ and loving it but there is a joke I don’t understand. Please excuse my silliness if it’s obvious.
“A little girl is taken to a restaurant by her parents. The waiter stands by while they read the menu. The little girl says, ‘I want a hamburger.’
“The mother looks over at the father. ‘How does a Greek salad sound?’
“‘Fine,’ he replies.
“‘We’ll have three Greek salads,’ the mother tells the waiter.
“Turning to the kitchen, the waiter shouts, “two Greek salads and a hamburger.’
“‘Look, mommy,’ the little girl exclaims. ‘He thinks I’m real!'”

If anyone else could please explain this for me I would be very grateful. I am loving the book and wouldn’t want to continue reading without understanding it.