It is quite difficult for an egotist to repent, for three reasons:

1) He constantly finds various justifications for his evil behavior, proving that, in all truth, righteousness is on his side.

2) If he does something so clearly wrong that he cannot wrap it in a mantle of uprightness, he attributes the fault to his environment or to his great evil inclination, etc. He thus remains blissfully free of responsibility.

3) If he does not find an external cause or a pretext for his evil behavior, he simply ignores it. “Love covers up all sins”.

A humble person, on the other hand, judges himself and renders a just verdict, without distorting facts or inventing transparent excuses.

(Likkutei Sichot, vol. 1, p. 130)