Never mind who was your grandfather. What are you? Pr.
Never morning wore / To evening, but some 50 heart did break. Tennyson.
Never neglect small matters and expenses. It. Pr.
Never offer to teach fish to swim. Pr.
Never preach beyond your experience. Pr.
Never put your arm out farther than you can draw it back again. Scott.
Never put your hand into a wasp's nest. Pr. 55
Never read borrowed books. To be without books of your own is the abyss of penury. Don't endure it. And when you have to buy them, you'll think whether they're worth reading; which you had better, on all accounts. Ruskin to a young boy.
Never repeat old grievances. Pr.
Never risk a joke, even the least offensive in its nature and the most common, with a person who is not well-bred, and possessed of sense to comprehend it. La Bruyère.