When you play chess, onlookers sometimes can read the progress of the game better than you. It is similar to the situation where people don't heed their own shortcomings very well, but they can quickly see the other's mistakes or faults. Such people can be often found in our daily lives. But wise people do not heed the other's shortcomings but instead they try to look back on themselves. "You hypocrite, first take the log out of your own eye, and then you will see clearly to take the speck out of your brother's eye" (Matthew 7:5).