Lent, the season of preparation for Easter, begins today. Traditionally, Lent is marked by prayer, fasting, self-reflection, and repentance. Lent is sufficiently serious that some Christian calendars have installed a season to prepare for it. It is called Mardi Gras. Whereas Lent projects a somber, almost lugubrious mood with a theme of denial and self-discipline, Mardi Gras is just the opposite. It is a time for parades, parties, and dancing in the streets.

The celebration called Mardi Gras is, of course, big in New Orleans, but I understand it is even bigger in Rio de Janeiro. The Brazilians call their festival Rio Carnival. Most businesses in the city close for a full week. Workers are given a holiday to attend this 24-hour per day colorful gala in the city streets. Every year five mil…