One year ago, Cardinal Jorge Mario Bergoglio from Argentina become Pope Francis. Upon his election, the new pope asked the crowd at St. Peter's Square at the Vatican, "Pray for me."

Since then, the 77-year-old pontiff, who took the name Francis after St. Francis of Assisi, has become a popular leader in part because of his informal and inclusive attitude. Positioning himself as a champion of the poor and disenfranchised, he has refused to live in the papal palace, rides the "popemobile" without the bulletproof glass casing, and urged priests not to drive expensive cars and give money to those less fortunate. His first year has been marked by events like his first Holy Thursday, when he washed the feet of young prisoners in an act of uncommon humility.

Many Catholics also have been encouraged to see that Francis has taken less hard-line positions on some issues than his predecessors. He has said he does not judge gay people as long as they "seek God and are of good will," and recently came out to say divorcees should not be condemned by the church.

Sally Wilson, a non-Catholic who recently traveled to St. Peter's Square from Texas, tells NPR that the pope has particularly wide appeal: "I think his serving humanity and his love of people have an effect that makes him feel like he's a pope for all, not just for Catholics."

But the real secret behind Francis's effectiveness may be the fact that people feel like he actually loves his job. 

Father John Wauck, a professor at the Opus Dei Pontifical University of the Holy Cross in Rome, tells NPR he has seen many popes, but what separates Pope Francis's leadership is his positive disposition.

"He is not a showman in the way John Paul was, and he's not retiring in the way Benedict was. Francis is completely comfortable in his own skin. He is transparently a happy person," Wauck says. "It sounds really simplistic, but unfeigned happiness on the part of a public figure is not that common."