There is a time and a place for nostalgia and, within an instant of Bill Clinton taking to the platform in Boston, it was obvious why he had been asked to speak on the opening night of the Democratic convention.
As he strode towards the podium - indeed, even before he had uttered a word - the former president displayed for the roaring crowd before him those unmatched political skills. His energy and effortless smile, his upraised hand and the hug with his wife who had just introduced him were the work of a hugely talented communicator. Mr Clinton, it is clear, is still very fluent in body language.
In terms of igniting the convention - and hitting the primetime television broadcasts - Mr Clinton was the perfect choice for Monday's opening night.
And for John Kerry, due to speak tomorrow evening, it was common sense to put as many days as possible between himself and this master orator in order to try to lessen the uncomfortable comparisons between them.
To be fair, Mr Clinton has done his utmost to try not to upstage Mr Kerry, whose oratorical and campaigning skills - while not necessarily poor - are no match for those of the 42nd president. Mr Clinton made clear that, after delivering his speech, he was immediately "getting out of town".
And, on Monday night, in a rousing yet disciplined 25-minute speech, Mr Clinton was prepared to use self-deprecation and humour as he argued why Mr Kerry had the leadership qualities to be next US president.
"During the Vietnam War, many young men - including the current President, the Vice-President and me - could have gone to Vietnam but didn't," he said. "John Kerry came from a privileged background and could have avoided it too.
"Instead he said, 'send me'.
"When they sent those Swift boats up the river in Vietnam, and they told them their job was to draw hostile fire, to wave the American flag and bait the enemy to come out and fight, John Kerry said, 'send me'."
Mr Clinton's words, which followed solid speeches by another former president, Jimmy Carter, and a former vice-president, Al Gore, as well as a hugely-applauded 11-minute address by Mrs Clinton, was crafted not just to boost the morale of party activists but to appeal to the crucial undecided voters across America whose votes Mr Kerry must win if he is to succeed in November.
He talked, therefore, not only of foreign policy - claiming that the Republicans squandered international support after 11 September - but of domestic issues such as law and order and homeland security. And while he never once mentioned George Bush by name, he used humour to criticise the President's tax cuts for the most wealthy in society such as himself.
"When I was in office, the Republicans were pretty mean to me," he said.
"When I left and made money, I became part of the most important group in the world to them. At first, I thought I should send them a thank you note - until I realised they were sending you the bill."
While there were undoubtedly many in the energised convention hall wishing they could turn back the clock, Mr Clinton urged that they look to the future. "Tonight my friends, I ask you to join me for the next 100 days in telling John Kerry's story and promoting his plans," he declared. "Let every person in this hall and all across America say to him what he has always said to America: send me."
Continuing his theme, Mr Clinton concluded: "Since we're all in the same boat, let us chose as the captain of our ship a brave good man who knows how to steer a vessel though troubled waters to the calm seas and clear skies of our more perfect union. We know our mission. Let us join as one and say in a loud, clear voice: Send John Kerry."
From the outset, Mr Clinton's appearance never bore the problems or theatrics of his participation in Al Gore's 2000 bid for the White House when the candidate was uncertain whether the Monica-tainted president would be an asset or a hindrance. On that occasion in Los Angeles, Mr Clinton arrived at the podium after a meandering walk through the bowels of the arena - broadcast live on screens. Even his closest admirers thought that it was over the top.
Four years on, it is perhaps a sign of Mr Kerry's assuredness that he was always happy to give Mr Clinton such a high-profile speaking slot at the convention. On the other hand, it may simply have been a recognition that in what is going to be a desperately close-fought contest, he needs every drop of Mr Clinton's charisma and energy to help the cause.
On Monday night in Boston, Bill Clinton proved that there there remains no shortage of that precious gift.
"All we wanted to do was to be one country, strong against terror, helping to heal those who were wounded and the families who lost their loved ones, reaching out to the rest of the world ... The President had an amazing opportunity to bring the country together under his slogan of compassionate conservatism, and to unite the world... against terror. Instead, he and his Congressional allies made a very different choice."
"I never thought I'd be so well-cared-for by the President and the Republicans. I almost sent them a thank-you note for my tax cuts, until I realised the rest of you were paying the bill for it, then I thought better of it.''