Know Thyself is not the same as Be Yourself, until the rubbish has been cleared out. Nowadays it is fashionable to say, "Don't try to be perfect. Be comfortable with yourself as you are!"
The lazy and those who have given up welcome this as an excuse for their (mis)behaviour.
One might as well say, "Don't try to make your bedroom spotless. Be comfortable with the mess and rubbish as it is." Who made the mess? Who made you the imperfect being that you are?
Better advice would be, "Spot your faults. Don't ignore them. Don't defend them. Get rid of them."
NEW PROJECT: WRITE A LIST OF YOUR FAULTS. See how many you can cross out in a week. (And how many new ones you discover).