Mistakes are their own instructors
For a man learns more quickly and remembers more easily that which he laughs at, than that which he approves and reveres.
One Sallow does not make Summer.
Change but the name, and you are the subject of the story.
Doctrina sed vim promovet insitam. Instruction enlarges the natural powers of the mind.
The poets aim is either to profit or to please, or to blend in one the delightful and the useful. Whatever the lesson you would convey, be brief, that your hearers may catch quickly what is said and faithfully retain it. Every superfluous word is spilled from the too-full memory.