Never thrust your sickle into another’s corn.
You never get a second chance to make a first impression.
I never saw a Purple Cow; I never hope to See One; But I can Tell you, Anyhow, I’d rather See than Be One.
Never hold discussions with the monkey when the organ grinder is in the room.
Never trust a man with short legs-brains too near their bottoms.
And therefore never send to know for whom the bell tolls; it tolls for thee.
Never lend books, for no one ever returns them. The only books I have in my library are books that other folks have leant me.
A caterpillar who seeks to know himself would never become a butterfly.
You fell victim to one of the classic blunders. The most famous is: “Never get involved in a land war in Asia.” But, only slightly less well known is this: “Never go in against a Sicilian, when death is on the line!”
Never be afraid to sit awhile and think.