It's a weird thing about America: when you live there, the rest of the world shrinks. The planet doesn't exactly vanish where the United States end, but the only places that matter are a scatter of tiny spots, littering the global map like a dot-to-dot puzzle or the pimples on a New Jersey teenager's face.

Dublin is one of the spots, and Rio de Janeiro is another: every American has an Irish ancestor somewhere, and all the best plastic surgeons are Brazilian. Mexico City is the place for a divorce, and Cuba is that island where the world's last evil Commie lurks. Berlin is on the map, because JFK went there and announced he was a doughnut ("Ich bin ein Berliner" doesn't mean "I'm a Berlin kinda guy").

When I rolled up at Stanford University in California in 1972, I thought the girls would be hooked by my tales of romantic wanderlust: I was a Tel Aviv boy, educated in Cyprus and famous in Switzerland, who'd picked up a few words of Italian from a sexy signorina in Sicily.

The girls hadn't heard of any of these places, except Sicily: that was in New York, right?

None of them would have been even slightly impressed to learn I was visiting the President if that President wasn't the one who lived in Washington's White House. Which is a shame, because I did meet a president this afternoon, the ruler of a sprawling nation with a bigger population than Britain's and cavernous diamond mines which outstrip even Shirley Bassey's wildest dreams... and this president was a more formidable and impressive figure than George W Bush could ever hope to be.

President Olusegun Obasanjo of Nigeria was in London to urge Tony Blair to write off Nigeria's loans and help him trace the mountain of gold stolen by his predecessor, General Sani Abacha. I was summoned to a private audience at the presidential suites of London's Hilton Hotel after my name was whispered by my royal friend: His Majesty Alaiyeluwa Oba Okunade Sijuwade, of the Aafin (or palace) in Ile-Ife, capital of Nigeria's Osun State.

The scene outside the president's apartments was extraordinary: the walls were lined with hopeful businessmen and eager petitioners, all prepared to wait for days for a few moments of the president's time, and all watched ceaselessly by the dark-garbed bodyguards.

As the king entered the room, everyone threw themselves to the floor.

They didn't merely bow - they knelt and stretched their arms across the carpet towards the king's feet. Even the bodyguards were prostrate.

I have visited Buckingham Palace and St Jame's Palace on several occasions, but the respect shown to the Queen and Prince Philip is entirely different to the devoted reverence Nigerians display to their king. I am only now beginning to understand what an honour is done to me and my family by the visits of my friend to our home. He is a gentle man without a speck of pomposity in his manner.

We were immediately shown into the president's suite, where he had evidently been told what to expect: a Hilton knife and fork of sterling silver lay on the table before his rolling sofa. President Obasanjo gestured for the king to sit on his right and me on his left, and watched impassively as the fork bent on the palm of his hand.

I offered to read his mind, and covered my eyes while he made a drawing and gave it to an aide to hide. When I invited him to transmit the image telepathically, I had a shock: all that was coming out of his brain was a scramble of white noise. I wasn't picking up even the dimmest outline.

I felt my face flush with embarrassment. It would be an unpleasant slice of humble pie, to tell the President, in front of the King, that I couldn't read his mind, despite all my boasts a moment before. But it would be far worse to take a wild guess and get it wrong.

President Obasanjo seemed unaffected by my failure. "I have a strong

mind," he remarked. I couldn't understand that at first, because most people think the strength of their telepathic signal reveals the intensity of their brainpower. Later, I remembered a similar failure, over a dinner table with Henry Kissinger.

Kissinger's mental transmissions were just as illegible, and his explanation was much the same: "There's a wall around my mind and I couldn't tear it down even if I wanted to."

Luckily I was able to leave the President with a successful demonstration. He wore a magnificent watch, and I asked him to lay it face up on the blade of the knife. Clenching my fist above it, I directed all my energy at the dial and shouted: "Move!"

The hands leapt around. In a few seconds, the watch gained an hour. It was a dramatic moment.