Any given generation gives the next generation advice that the given generation should have been given by the previous generation but now it's too late.
Roy Blount, Jr. (2009). “Alphabet Juice: The Energies, Gists, and Spirits of Letters, Words, and Combinations Thereof; Their Roots, Bones, Innards, Piths, Pips, and Secret Parts, Tinctures, Tonics, and Essences; With Examples of Their Usage Foul and Savory”, p.27, Macmillan