And That's When He Knew His Patient Was a Dork

I just started reading "The Meaning of Everything: The Story of the Oxford English Dictionary," which is fantastic thus far. I was reading it while waiting for the dentist this morning. While he was holding something in my mouth, he asked me to turn over the book so he could read the back.

Dentist: You're reading that for school, right?
[I shake my head no, which is the best I can do because his hands are in my mouth.]
Dentist: You're reading that for fun?!
[I nod yes. His hands are still in my mouth.]
Dentist: What's so special about the Oxford English Dictionary?
Me: [Finally] I mean, it's a great dictionary.
Dentist: [Very skeptically] Um... OK.