The Sin of Lucifer

In the ongoing and ever-losing battle with my own personal dragons of pride, I took to wondering: why is the proud man angry or peeved with the stupidity (real or imagined) of his fellows?

I ask because one would think a saint would be very patient with someone who was stupid, if it were honest stupidity, and not merely laziness in thinking. Whereas the devil (or Lex Luthor) is always in a state of haughtiest annoyance, because he is brighter than those around him. Their stupidity proves his superiority – yet it irks him. Why?

This is not a rhetorical question: I do not have a theory on the subject myself.