“Socrates: Observe, Meno, the stage he has reached on the path of recollection. At the beginning he did not know the side of the square of 8 feet. Nor indeed does he know now, but then he thought he knew it and answered boldly - he felt no perplexity. Now however he does feel perplexed. Not only does he not know the answer; he doesn’t even think he knows.”
Plato’s Meno 424-347 BCE