Emma Jane Kirby reflects on why the unpredictability of Nicolas Sarkozy makes it difficult to define him.
Mr Sarkozy became president in May 2007
It seems to me that almost every day, someone here coins a new nickname for the French president.
Many are just variations on the same theme.
His smallish stature has prompted scores of fairly predictable titles along the "dwarf", "mini-me", "built-up heels" variety and his unpopular policies have generated myriad epithets ranging from "Sarko the American" - referring to his fondness for closer transatlantic ties - to the more generalised "iznogoud" (pronounced "is no good" with a French accent), to the pretty all-encompassing "heap of dog's muck".
But what strikes me is that no-one really seems to agree on who or what Nicolas Sarkozy is.
If this was a French musical, perhaps now would be the moment when an exuberant nun or Mother Superior might burst into the song: "How do you solve a problem like Sarkozy?"
But since there are no willing Sisters in the vicinity, I shall try myself to catch the French leader and pin him down.
But how do you define a man who is at once described as "Super Sarko" and "Sarko the smurf", as "Nico Napoleon" and "Nico the nervous"?
The short answer, I believe, is that you cannot and this is exactly what makes the leader of the Fifth Republic such an infectiously alluring character.
Last summer I went to visit the cartoonist Jul at the satirical newspaper Charlie Hebdo.
I remember asking him how he set about drawing the president and whether he had any characteristics that really stood out.
Jul told me that when his subject matter was Nicolas Sarkozy, he could never plan his comic strip in advance.
The president, he said, was like a chameleon that changed every five minutes and if he drew too far ahead of time, his cartoon would simply be out of date.
And apart from one satirist who routinely draws Mr Sarkozy as the devil - albeit in a thousand disguises - it seems that none of Jul's fellow artists can classify or categorise him either.
While one is portraying him as the confident King of Bling, another is sketching him as a sad puppy rejected by women.
And that is exactly how President Sarkozy likes it. Predictability is not a word he recognises.
French journalists constantly complain they are unable to cover his story sufficiently because he is always on the go.
On Monday afternoon he is in Lille talking about the car industry, on Tuesday morning he pops up in Iraq.
The ink has barely dried on the headline "Protectionism" when the typeface has to be reset to "Reconstruction".
Get up close and you are not even sure you are following the same man as yesterday
And then quite suddenly he is on three television channels simultaneously, addressing the nation about the economic crisis.
It is an exhausting, punishing schedule... at least for those of us who are charged with reporting him. But the French leader himself appears to take it all in his stride. A keen jogger, he enjoys keeping the nation on its toes.
Catch me, he seems to be saying, if you can.
But you will never catch him. Get up close and you are not even sure you are following the same man as yesterday.
Apart from the children's TV character Mr Benn, who regularly visited a dressing up shop and became a different person each day, I can think of no-one who reinvents himself so frequently.
In just over 18 months of office President Sarkozy has already been the "happily-married-family-man", the "macho-man" (jogging round Paris in a sweat-stained New York Police Department T-shirt), the "business-man" reclining on yachts and dripping in Rolex watches and "super-man", heroically rescuing French hostages in Libya.
When his ex-wife was speedily replaced by the classy former supermodel and pop star Carla Bruni, there was a new metamorphosis. Nicolas Sarkozy began to read the classic literature he had previously scoffed at, he began to talk about the importance of faith in society and his explosive temper softened.
"I've changed," he told stunned reporters brusquely. And that was that.
The first time I met the French leader, at an Elysee news conference with Gordon Brown, we did not see eye-to-eye.
Mr Sarkozy has recently questioned the UK's economic rescue package
I had asked the new prime minister whether he envisaged any problems working with Nicolas Sarkozy, who did not exactly share his own views about economic liberalism.
Although my question was not addressed to him, President Sarkozy took the microphone anyway and jabbing his finger at me angrily he swiftly qualified his views on competition, clearly irritated that I had dared to imagine I knew what his opinions were.
Just before Christmas I found myself again in a press conference at the Elysee with the same two leaders and as I was sitting in the front row. Nicolas Sarkozy caught my gaze.
He gave me a small but not unfriendly smile and then slowly, deliberately, he winked.
You think you are on to me, he seemed to be saying. And while I may know who you are, you will never know me.
From Our Own Correspondent was broadcast on Saturday, 28 February, 2009 at 1130 GMT on BBC Radio 4. Please check the programme schedules for World Service transmission times.