Nothing hurts the ego.

It's simply a shield which guards the consciousness of the mind from what it knows subconsciously which could make said mind feel insecure, uncomfortable.

This includes willful blindness to truths and established facts.

The ego manifests self defense strategies for the conscious mind. Usually extremely prevalent in thin-skinned, bold-faced liars whose character is paper thin - almost translucid. These type tend to benefit most from denial.

:)