As Bernard Shaw said, “He who can, does: he who cannot, teaches.” But, as Sydney J. Harris put it, “Let’s revise Shaw’s foolish saying to ‘He who can… - Sydney J. Harris

One of the most frequent mistakes we make lies in assuming that personality is a collection of traits, or that a personality is merely the sum of its parts. Personality is a way of organizing these parts...If we look at persons dynamically, and not simply as a static set of traits, we can see that certain defects are the price they pay for their virtues...This is why “pointing out” a bad trait to a colleague or a subordinate - even in a kindly and a well-meaning way - usually does no good, and may even do some harm. It makes him feel worse, and does not enable him to act any better.

Experience can be a very bad teacher, indeed, or not teacher at all. It is like the silly phrase, “Practice makes perfect.” In most cases, practice merely confirms us in our errors, and the longer we do something the wrong way - that is, without enlightenment and instruction- the more fixed we become in our folly.

"But if "beauty" is in the eye of the beholder, so is "obscenity.