Pope Francis belongs to the Jesuits, a religious order whose members take an unusual — and at the moment seemingly ironic — vow: not to strive for a higher office.

The Jesuits' culture of modesty and self-effacement has been on full display in recent days, with Catholics worldwide regaled by reports that the new pope had opted to take the bus back from Vatican City's Sistine Chapel with the other cardinals and then stopped by his hotel to pay his tab.

For Jesuits and people who have gone to Jesuit-run schools or who belong to parishes run by the order around the world, the concept of one being at the helm of the Catholic Church has required some mental gymnastics.