It is a good job that Mary Pierce has, at last, begun to understand herself because none of the rest of us has a clue what makes her tick. She is that marvellous mixture of potential Grand Slam champion - she reached the French Open final a few weeks ago - and potential first round loser. The bizarre array of nervous twitches, tics and tremors are interspersed with belting winners that could knock lumps out of everything in their path, opponents included. It all depends on Mary.
Her quarter-final encounter with Venus Williams told you all you need to know about the great Miss Pierce. For a set she was awful - 21 minutes in which time she earned a paltry 11 points and lost the set to love - and for a set she almost had Williams beaten. Had the match gone into a third set, who knows what would have happened? Pierce being Pierce, she could as easily have lost it 6-0 as won it 7-6.
Most players would take a first set hiding as sign that this was not to be their day. A combination of embarrassment, disappointment and the overwhelming desire to be somewhere else would be too much to bear. But most players are not Mary Pierce. She must be the only player in history to take a 6-0, 6-0 pasting from Jennifer Capriati (in Rome three years ago) and then declare: "It does give me a lot of confidence." That's our Mary.
These days Pierce is a happy woman. Relaxed, at peace with herself and at last free of injury, she is having the time of her life. Getting to the final in Roland Garros was a fabulous run, a chance to relive her past and a chance to prove that, at the age of 30, she is not done yet. Only in the final did she let herself down but the way she got there was impressive and, as ever with Pierce, highly entertaining to watch. Only Pierce could miss nine match points in the fourth round and find it funny. She found it an absolute hoot when she converted the 10th.
As for taking on the youngsters, Pierce is reckons that age actually helps. She can remember what it was like to be a teenage hopeful stepping on to the big stage and trying to cause a major upset - and it was scary. Having been through it herself, and these days being classed as the underdog, she can use that knowledge to her advantage.
She has been though many ups and downs in her career but now, with nothing to lose and nothing left to prove, she can just enjoy the moment. This year that has brought her the best set of results she has had since she won the French Open in 2000.
"To only be 30, I feel like I've already lived three lives," she said. "I just really try to learn a lot every day, try to grow as a person, you know, as much as I can really."
Written by Alix Ramsay