Am I vertically challenged???

Today I was taking Felipe to school and since I didn't have to go to work I had Francesca with me also in the car.

The conversation goes like this...

Felipe:  Is daddy 37?
Me: Yes
Felipe: Why is daddy not like you?
Me:  He is, I am also 37.
Felipe: No, why isn't daddy like you?
Francesca: What... Tiny?
They both start to laugh and I call Adrian to tell him and he tells me that I am not tiny I am just vertically challenged.

The most interesting part of all this is that I still don't know what Felipe meant by his question.