In any situation there are two witnesses: other people's view of you and your own view of yourself. Of those, the principal witness is your own insight. You should not go along with other people's opinion of you. The practice of this slogan is always be true to yourself.
...
You know best about yourself, so you should work with yourself constantly. This is based on trusting your intelligence rather than trusting yourself, which could be very selfish. It is trusting your intelligence by knowing who you are and what you are. You know yourself so well, therefore any deception could be cut through. If someone congratulates or compliments you, they may not know your entire existence. So you should come back to your own judgment, to your own sense of your expression and the tricks you play on others and on yourself. This is not self-centered, it is self-inspired from the point of view of the nonexistence of the ego. You just witness what you are. You are simply witnessing and evaluating the merit, rather than going back over it in a Jungian or Freudian way.

From TRAINING THE MIND by Chgyam Trungpa, 1993 by Diana Mukpo.
Published by arrangement with Shambhala Publications, Inc., Boston.