Thoreau, in Walden, on borrowing an axe: "The owner of the axe, as he released his hold on it, said that it was the apple of his eye; but I returned it sharper

Thoreau, in Walden, on borrowing an axe: "The owner of the axe, as he released his hold on it, said that it was the apple of his eye; but I returned it sharper than I received it." A high school English teacher used this passage to impress upon us this same philosophy of "leave it nicer than you found it" (in particular, I remember him telling us that our parents leave us in his care and he saw it as his job to "return us sharper than we were received") and it's one of those rare moments that made such a deep impression on me I remember it often even decades later.