Busy

David doesn't know the meaning of the word "Busy." He thinks he does, though. He says "busy" in a determined way. I cannot figure out what he means when he says this. In the past he has said over and over, "Momma, I'm busy. I'm busy Momma." This is usually said in desparation. He never seems to be doing much but sometimes he has been running around at the time. I have asked him, 'David, are you dizzy?' Which is followed by a "No, momma, I am BUSY."
Tonight the meaning of the word to David was even more elusive to me.
We were at a neighborhood park. David ran up to me a couple of times saying he was his belly was BUSY.
David: "Momma, my belly is busy."
Momma: "Your belly is busy?"
David: Yes, my belly is BUSY."
Momma: "David does your belly hurt?"
David: "No momma, my belly IS BUSY."
Momma: (Noticing he was a bit out of breath) "David, is your belly tired?"
David: "NO, MOMMA, my belly is BIIIIIISY!" (David runs back to play.)