By Andrew Walker
BBC's News Profiles Unit
The man once dubbed "the accidental president" celebrates his 60th birthday on 6 July. But, in the middle of his second term, George W Bush still has a fight on his hands to both define, and secure, his legacy as 43rd president of the United States.
President Bush: Into his seventh decade
Say what you like, but there's no doubt that more than six years into his presidency, George W Bush's grasp of the English language remains resolutely singular.
Just last week, playing host to Junichiro Koizumi, the Elvis-obsessed prime minister of Japan, Dubya gave yet another master class.
"I reminded the American people, Mr prime minister, over the past months that it was not always a given that the United States and America would have a close relationship," he said. "After all, 60 years ago we were at war."
But, joking aside, the US still is: its self-proclaimed "War on Terror" has seen more than 2,500 American troops killed and another 18,000 wounded in Iraq.
Its detention centre at Guantanamo Bay on Cuba has been condemned throughout the world and the US Supreme Court has just ruled that trying alleged terrorists in military courts is illegal.
Millions of people have demonstrated against the Iraq war, the US and its traditional allies in Old Europe have fallen out as never before, and the American people have reacted by damning their president with approval ratings hovering in the mid-30s, lower than any since Richard Nixon was mired in Watergate in the mid-1970s.
Birthday boy: The president was presented with a cake on 4 July
And, at the eye of the storm, sits the birthday boy, still chipper, still confident and still firm in his belief in America as leader of the free world.
The president reaches three score years in robust physical health. Recently reckoned to be in the top 1% of men of his age, he works out six days a week: cycling 15 to 20 miles - he gave up running after knee problems - walking on a treadmill, using an "elliptical trainer", lifting weights and stretching.
He can still boast 20-20 distance vision but uses reading glasses. His only other medical condition seems to be oesophageal reflux - stomach acid flowing into the throat - which is kept under control by medicine.
All of which is quite remarkable, especially considering the well-documented excesses of his youth.
Even so, President Bush still has off days. Last July, while at the G8 summit in Scotland, he lost control of his bike and crashed into a police constable, injuring the officer's ankle and scraping his own hand.
He's also fallen off a Segway scooter, crashed his mountain bike in Texas and, most famously, passed out after choking on a pretzel while watching American football on television.
The "Boomer-in-Chief" shares his birth year with a raft of celebrities including Diane Keaton, Donald Trump, Bill Clinton, Cher and Sylvester Stallone - the first wave of some 78 million US Baby Boomers to reach the big Six-O.
Pedal power: The Commander-in-Chief is a keen cyclist
And that, in itself, is cause enough for concern for the Chief Executive. An ageing US population is set to impose an unprecedented strain on the country's already creaking social security and Medicare systems, something the president has long promised to deal with but has, as yet, failed.
Now, looking forward to his remaining 31 months in the Oval Office, President Bush's thoughts must be dominated by how he is remembered by history. There are many loose ends to tie up before we have a flavour of the legacy left by the 43rd president.
Most of his predecessors have left their own individual mark: Johnson's social reforms, Nixon's diplomacy, Reagan's perceived victory in the Cold War and Clinton's economic boom.
But GW Bush still faces an uphill battle to define his time in the White House.
Economically, the US is sending out mixed signals. Although growth is high, running at nearly 5%, so are interest rates (5.25%) and the vast trade deficit, currently more than $60bn a month, must be a concern.
And, although he has vowed to get government spending under control, the jury is still out.
On immigration, Bush favours a dual-track approach, securing US borders before offering illegal immigrants guest worker status or a formal path to American citizenship. But this potential landmark legislation is currently stalled in Congress.
Perhaps Dubya's greatest hope of leaving a strong legacy now resides in the foreign sphere. Notwithstanding his travails in Iraq, any success in extricating US troops and facilitating an independent Iraq by 2009 might be seen as some form of achievement.
Eschewing talk of withdrawal, he told troops on 4 July: "This moment, when the terrorists are suffering from the weight of successive blows, is not the time to call retreat. We will stay. We will fight. And we will prevail."
Bush is looking to his legacy after life in the Oval Office
And he has shown no lack of faith in continuing to espouse the benefits of democracy to everyone from Middle Eastern rulers to Russia's President Vladimir Putin.
But the American people remain to be convinced. November's mid-term elections are set to be a crucial test of support for Bush's Iraqi adventure.
The Republicans' majorities in both Senate and House are under threat as voters look set to hammer the president's supporters, creating a lame duck presidency which will effectively scupper Bush's ability to pass legislation.
But, judging by his quips about joining the ranks of "the grey-haired folks", surely none of this will cloud the president's 60th birthday celebrations. And, who knows, he might even break one of his most famous habits and stay up after 9pm.