Sometimes the "fault" that you perceive in another isn't even there. It is a total misinterpretation, a projection by a mind conditioned to see enemies and to make itself right or superior. At other times, the fault may be there, but by focusing on it, sometimes to the exclusion of everything else, you amplify it. And what you react to in another, you strengthen in yourself.

Eckhart Tolle

from A New Earth: Awakening to Your Life's Purpose