"There's a Man Named Ralph..." joke

There's a man named Ralph that goes into a bar, looking very depressed. A friend approaches him and asks, "Why the long face, Ralph?"
"Oh, I'm just bored. I know every person in the entire world now, and there's just nothing left to challenge me."
His friend says, "No, you can't know everyone. Do you know Paul McCartney?"
He says, "Sure, Paul's an old friend of mine. Here, I'll show you." He goes over to a phone, dials a number. His friend overhears a British accent, "Hey Ralph, how ya doing?"
He talks for a while, but when Ralph hangs up, his friend is not really sure that it was Paul McCartney on the other end of the line, so he asks him if he knows the president.
Ralph says, "Sure, we go way back." This time he lets him listen in as he calls a private number. It sounds like the president on the other end of the line, and they go into a big discussion of the current economic scene, and Ralph offers a few suggestions. Drawing the conversation to a close, Ralph wishes him well and hangs up.
His friend is a little dumbfounded at this point. "Well, there must be someone that you don't know." He goes over a few more people in his mind, and thinks, 'He can't possibly know the Pope. After all, he's a Protestant.'
But Ralph claims to know him, so to convince himself otherwise, his friend decides to fly both himself and Ralph to the Vatican to get positive proof of Ralph's conviction.
So they arrive at the Vatican, and Ralph suggests that his friend wait out in the Papal square until Ralph has cleared things with the Pope. He's standing in the courtyard, when who walks out onto the balcony of the private residence, arm in arm with the Pope, but Ralph.
Ralph looks down, sees that his friend has apparently passed out, and runs down to see what can be done for him. "What happened to you? Couldn't you accept the fact that I really do know the Pope?"
"No, I'd begun to accept that possibility. But what really took my breath away was some stranger standing next to me who said, 'Who's that guy standing there with Ralph?'"