So, on the way to school, I asked him for some more details.
Me: Can you remember all those periods you have on your computer about when the dinosaurs lived?
Ev: You mean the three periods that dinosaurs lived in?
Me: Uh, yeah.
Ev: Triassic, Jurassic, and Cretaceous.
Me: Oh. Well can you remember all those others?
Ev: Ummmm, Quaternary, Tertiary, Cretaceuos, Jurassic... did I say Tertiary?
Me: I think you did.
Ev: Triassic, Permian, Devonian, and... I think there's only one left - Carboniferous!
Me: Wow. That's impressive.
Ev: Quietly continues reading on way to school.
It is a humbling experience to be made proud of your nine year old son and also shamed by him in a single conversation.