Vatican City: Starting with the historic moment when the first Latin American pontiff greeted the crowds in St Peter’s Square after his election on Wednesday, Pope Francis has shown a lively sense of humour.

The smiling 76-year-old waved his hand in the air to underline a point about just how far the cardinals who elected him had looked to find a new pontiff.

“It seems that my brother cardinals have gone to the other end of the world to get one! But here we are,” he said in what is becoming a trademark informal style from the newly minted leader of the world’s 1.2 billion Catholics.

He later told cardinals over dinner: “God forgive you for what you’ve done!”

In a phone call to an Italian journalist friend that same night he laughed out loud when she asked whether she should start calling him “Holy Father” - the standard style for popes - instead of just “Father” as before.

Quipping was definitely not on the cards with Francis’s predecessor Benedict XVI, who rarely strayed from prepared texts and was fond of delivering theological treatises in public, although he was said to reveal an ironic wit in private.

Pope Francis “is very relaxed and behaves in public just like he would in private,” said Marco Politi, a Vatican expert, who said the new pontiff seemed “very at ease and very natural” and had decided to just “be himself”.

Speaking to pilgrims in St Peter’s Square on Sunday, Francis cited a book by German cardinal Walter Kasper, then said: “Don’t think I’m plugging my cardinals’ books, eh? It’s not like that!”

He then recounted the story of an elderly Argentine woman who had told him that if God did not forgive sins, the world would not exist.

“I felt like asking her: did you study at the Gregorian?” he joked.

The Pontifical Gregorian University in Rome is an intellectual training ground for Catholic leaders run by the same Jesuit order Francis belongs to.

The tango-loving Argentine pope’s humour shone through the previous day too in remarks to the world’s press when he broke off from a prepared text to gaze around a Vatican auditorium and said: “You’ve worked, eh? You’ve worked!”

Francis also departed from papal tradition by revealing a few details of the supposedly top-secret deliberations among cardinals that led to his election.