A loyal friend tells you the haircut was a mistake, then helps you survive the six weeks it takes to grow out.

Honesty and sympathy are supposed to arrive together. Telling somebody a decision went badly is only half a job; anybody can deliver a verdict and walk off, and that is closer to criticism than friendship. The second half is staying around for the consequences, which in this case means six weeks of hats and not bringing it up in front of people.

When you tell a friend something they will not enjoy hearing, say it once and then be useful. Stop commenting after the first time. And when you are the one living with the mistake, keep the friend who told you the truth.