The Pope and Queen Elizabeth were standing on a balcony, beaming at the thousands of people in the courtyard below. The Queen said to the Pope out of the side of her mouth, "I bet you a tenner that I can make every English person in the crowd go wild with just a wave of my hand."
The Pope replied, "No way! You can't do that." The Queen said, "Watch this!" So, the Queen waved her hand and every English person in the crowd went crazy, waving their little plastic Union Jacks on sticks and cheering like mad.
The Pope was standing there thinking, "Oh no, what am I going to do? I never thought she'd be able to do it." He thought to himself for a minute, and then turned to her and said, "I bet you I can make every Irish person in the crowd go wild. Not just now, but for the rest of the week, with just one nod of my head."
The Queen replied, "No way, it can't be done."
So, the Pope head-butted her.