Human nature is a pesky thing. Because it's fallen, it can sometimes undermine or sabotage our work as apologists in ways that we easily miss. One of the ways this can happen is through triumphalism, defined as the spirit of arrogance or pride with respect to belonging to the Church. Not the proper sense of pride, a la "I'm proud to be Catholic," but the self-puffery sense, a la "I belong to the One True Church, and you don't." Whether subtle or overt, it’s lethal to the work of evangelization.
When sharing the Faith with people, we should err on the side of humility. As all spouses know, the great bulk of communication (for good or for ill) has to do with tone of voice, body language, eye contact, and the like. This is what media guru Marshall McLuhan was getting at with his famous maxim "The medium is the message." Pope Paul VI expanded upon this idea in his 1975 Apostolic Exhortation Evangelii Nuntiandi, where he used the word witness 36 times in the course of explaining that the modern world is craving living examples of Christian living. I don’t become a living example by just reading a book. I become one by living the sacramental life in a way that—very directly—allows Christ to live his life in me. So says St. Paul in Galatians 2:20.
This is what makes converts. This is what those around us are eager to see. Not that intellectual formation is worthless; it is necessary, often thrilling, but it's insufficient.
When triumphalism seeps in, we lose, even if we "win" the argument. By contrast, the attitude that invariably delivers the eureka moments for people is the one that conveys the flavor of "I can hardly believe that a sinner like me has found such a rich treasure of mercy and truth." Or as Mother Miriam of the Lamb of God puts it: "It’s one beggar telling another beggar in the desert that he has found cold water."
Who can argue with that?