We need to think about our own faults because if we are not aware of them we shall not be motivated to overcome them. It was through constantly examining their minds for faults and imperfections, and then applying great effort to abandon them, that those who are now enlightened were able to release their minds from delusions, the source of all faults. Buddha said that those who understand their own faults are wise, whereas those who are unaware of their own faults yet look for faults in others are fools.
Geshe Kelsang Gyatso - “Eight Steps to Happiness” (via dancingdakini)