Thinking highly of oneself isn’t pride – it’s vanity. Pride is thinking critically of others, in comparison to oneself. That’s why pride is so often unaware of itself, and only revealed in our attitude towards others.
Implicit in every judgment of others is an element of pride, because judgment necessarily assumes a position of elevation over the one being judged. Those whose fundamental attitude towards the world is judgmental are riddled through and through with pride, though none of us is innocent here, and those few whose approach to innocence is nearest are mainly regarded as fools. The fact that pride is principally other directed is why even those of no achievement can be prideful; pride is in fact perhaps nowhere more common.
Pride is the Original Sin, and it is an inheritance, not of genetics, but of self-directedness, a blossoming awareness of separation from others, from the world, and from God, along with the pain of that separation. Pride is the demonic analgesic of that pain.
There is no worldly riddance from it; the myriad of attempts to do so are the text both of the human comedy and the human tragedy. It is an existential dilemma, a Catch-22: Would you be human, then must you be self-oriented, with the fear and defenses that entails. Hell is our condition, our starting point, not our destination.
The only solution to the dilemma is to lose self-centeredness. When Jesus tells us that we can’t even see the Kingdom until we become (again) like children, that’s what he’s talking about. When he speaks of regaining our family through following Him, that’s what he’s talking about. When He speaks of the greatest love being loss of one’s own life, that’s what He’s talking about.
The long and winding road back to childhood is the Way of Christ.