The sin of pride is an inordinate love of self -- a super-confidence and high esteem in your own abilities. It's also known as vanity. It exaggerates your abilities, gifts, and talents, and ignores your weaknesses, frailties, and imperfections.
In Catholicism, sinful pride is the deviation or distortion of the legitimate need of self-affirmation. Liking yourself isn't sinful. In fact, it's healthy and necessary, but when the self-perception no longer conforms to reality, and you begin to think that you're more important than you actually are, the sin of pride is rearing its ugly head...
Pride is the key to all other sins, because after you believe that you're more important than you actually are, you compensate for it when others don't agree with your judgment. You rationalize your behavior and make excuses for lying, cheating, stealing, insulting, ignoring, and such, because no one understands you like you do. In your mind, you're underestimated by the world.
That's the extreme expression of pride. A subtler example is when you refuse to accept the authority of someone else over you, be it a parent, teacher, employer, pastor, bishop or pope. Most resentment toward those in authority has nothing to do with the occasional instances of abuse of power in the course of human history. Rather anti-authoritarianism is rooted in pride: "No one is going to tell me what to do." ...
Pride also prevents you from seeking, listening to, or applying advice from others. It fools the mind into thinking that it alone has or can discover all the answers without help from anyone...
The Catholic Church teaches that humility is the best remedy for pride. It's not a false self-deprecation ... It's not denying the truth ...
In other words, although acknowledging your talents is good, humility should remind you that your talents come from God. Pride fools you into thinking that you're the source of your own greatness.
Catholicism For Dummies by John Trigilio
Recommended reading: Back to Virtue by Peter Kreeft. He examines the virtues in depth and also looks specific virtues and Beatitudes as antidotes to each of the seven deadly sins. Not a new concept but one that he writes about superbly (as always).Next up: Envy.