Socrates learns about Zeroes
"'Those are numbers? How do they work?'
I wrote them down in the dust, from one to ten, and showed him. 'That's all there is to it.'. . .
He understood it at once. 'And you have all known all this time and never mentioned it to me?' he said.
'It never occurred to me that you didn't know,' I said.
'Pah. My ignorance is vast and profound. I like to know at least what I do not know.'"
ETA, not because it has to do with numbers, but just because I like the quote:
"'They're not. They're tools. Everyone knows that.'
'What everyone knows, Socrates examines.'"