C.S. Lewis, Mere Christianity, chapter 8:
There is one vice of which no man in the world is free; which every one in the world loathes when he sees it in someone else; and of which hardly any people, except Christians, ever imagine that they are guilty themselves.
I have heard people admit that they are bad-tempered, or that they cannot keep their heads about girls or drink, or even that they are cowards.
I do not think I have ever heard anyone who was not a Christian accuse himself of this vice.
And at the same time I have very seldom met anyone, who was not a Christian, who showed the slightest mercy to it in others.
There is no fault which makes a man more unpopular, and no fault which we are more unconscious of in ourselves.
And the more we have it ourselves, the more we dislike it in others.
The vice I am talking of is Pride. . . .
. . . In fact, if you want to find out how proud you are the easiest way is to ask yourself, “How much do I dislike it when other people snub me, or refuse to take any notice of me, or shove their oar in, or patronise me, or show off?”
The point is that each person’s pride is in competition with every one else’s pride.
It is because I wanted to be the big noise at the party that I am so annoyed at someone else being the big noise.