Book Critic

I teach a pair of brothers on Saturday mornings.  While I was teaching the younger, the dad handed one of my books (This is Your Brain on Music, by Daniel Levitin) to the older boy, who's about 14.  At the end, I heard this:

Dad: What do you think of the book?
Boy: meh... it's ... [insert teenage mumbling]
Dad [all enthusiastic]: It's written by a neurologist, about the different ways your brain connects neurons.
Boy [dismissively]: Yeah... he could have done better with metaphors.
Dad's jaw drops.