I remember the dinosaur days. DS was always extremely precise and could tell just about any dinosaur from sight. I could never remember how to pronounce Quetzalcoatlus (which, he was quick to point out, wasn't actually a dinosaur).

The need for precision doesn't go away, at least not by 7. Just about 5 minutes ago, he asked me to choose between three things. Not paying very much attention, I said, "Neither." He said, "That's not a choice. You mean 'none of them'?"