What do you do when you’re the Catholic Church, a millennia-old institution with rituals designed for every moment, and your pope retires for the first time in modern history and there’s zero script?

Well, you’re forced to kind of wing it. That was the scene in Italy exactly one year ago Friday, when Pope Benedict XVI officially left the papacy, the first pope to retire in 600 years.

Students at Catholic University in Northeast D.C. got a cool behind-the-scenes look Thursday night at how church officials dealt with reporters asking questions to which there were no obvious answers: How do you mark the moment the pope officially retired? If they normally seal the papal residences when a pope dies until a new one is picked, will Benedict be shut out of any of his living quarters?

The Rev. Thomas Rosica, a Vatican communications adviser, cracked up the room of about 100 students with a presentation on the crazy questions that some of my fellow reporters were asking a year ago as the world tried to figure out how to deal with this new business of a pope retiring. Rosica described how church officials essentially created the ritual around Benedict’s departure last Feb. 28: his helicopter landing at the papal vacation retreat of Castel Gandolfo, Benedict walking through the gates, the gates closing and the guard walking away from thousands gathered there.

Benedict had said he would retire at 8 p.m. that day, but there was no ritual or liturgy prepared for such a moment.

Rosica, who runs the Toronto-based Catholic television station Salt and Light, recounted the dramatic scene earlier when Benedict left Rome, his helicopter lifting up and flying twice around the cupola of St. Peter’s Basilica. Romans on rooftops all around were holding mirrors to reflect light off the sun, priests nearby were crying, Benedict’s driver was kneeling.

“It was such a sad day,” Rosica said.

He described the major culture shock going on days later, after Pope Francis was picked. Rosica was in the Vatican translation room with people who transcribe and publish papal comments during regular blessings at St. Peter’s Square.

On Francis’s first Sunday as pope, he ended his comments to the thousands of people there by saying in Italian: “Have a nice Sunday and a nice lunch.”

A translators accustomed to a more formal script “almost had a heart attack,” Rosica recalled. “ ‘A pope can’t say that!’ she said. I told her: ‘He just did.’ ”