Reading and Whales

In the car this morning:
Colby: "I read a 700 page book."
Mom: "No you didn't.  I've never seen you read a 700 page book."
Colby: "I did at school."
Mom: "I don't believe that.  What book was it?"
Colby: "I read Moby Dick."
Mom: "You did not."
Colby: "Yes I did.  I read Moby Dick."
Mom: "What is the Captain's name?"
Colby: "Uhhhhhhhhhhhhh, I don't remember."
Mom: "Right.  Ahab.  What is it about?"
Colby: "A whale."
Mom: "What kind of whale?"
Quinn: "Duh.  A DICK whale."

OK.  What do I say to THAT????