The Church has reintroduced a sacred gesture in the Mass: it's the gesture of sriking your breast as we confess to God & to one another that we are sinners as we say, "through my fault, through my fault, through my most grievous fault." It's a biblical gesture used in Jesus' time to express sorrow for one's sins. In the parable, Jesus said the tax collector beat his breast as he asked God for mercy.
We spend so much of our lives trying to prove to others, to ourselves, and maybe even to God, that we are better than others, just as the Pharisee thought of himself.
Archbishop Fulton Sheen used to work with the incarcerated but knew that as he stood before 2000 inmates, they thought he had on a white hat while they were all wearing black hats. So he said to them: "Gentleman, there is one great difference between you & me: you have been caught, I was not. In other words, we are all sinners." This is the attitude Jesus encourages through the parable. Pray humbly. Think of others as greater than yourself. Or as the ancient prayer goes, say "Lord Jesus Christ, Son of the Living God, have mercy on me, a sinner."