Experience becomes generous when it saves somebody else from paying full price for the same lesson.

Most hard-won lessons cost something real: time, money, embarrassment, a relationship. Passing them on lets someone get the benefit without paying the same price, which is one of the few ways that cost can produce something beyond your own life. Experience kept private only ever pays once.

Think of a lesson you paid dearly for and one person who is heading toward the same bill. Tell them. Do it without lecturing, simply as information they can use or ignore.