Cato the Younger

When, accordingly, he came to study, he was sluggish of comprehension and slow, but what he comprehended he held fast in his memory. And this is generally the way of nature: those who are well endowed are more apt to recall things to mind, but those retain things in their memory who acquire them with toil and trouble;[*](Cf. Aristotle, De Mem. i. 1, 2, 24.) for everything they learn becomes branded, as it were, upon their minds.