While filming the TSN/W5 documentary profile of Georges St-Pierre -- also known as "GSP" -- I had the privilege of travelling, eating, training and living with one of the great combat athletes in human history.

Up close and personal, I could study this brilliant martial artist in the hopes of seeing what it takes to achieve greatness in a field.

And, in GSP's case, it really comes down to three things: the constant search for one's own weaknesses, the joy in discovering them, and the commitment to improvement when you find them.

That dedication to self-improvement reaches all the way back to GSP’s youth in his hometown of Saint-Idisore, Quebec, when he was bullied at school.

“There were a group of delinquent teenagers and they were picking a lot on the younger guys,” GSP said in his interview.

“I used to fight every week. Most of the time, it didn’t go my way.”

GSP took up karate, which gave him the confidence to stand up to his tormentors. He progressed to become a Canadian junior karate champion and from there to mixed martial arts, establishing himself as the three-time welterweight champion of the Ultimate Fighting Championship (UFC).

But fear and self-doubt have followed him every step of the way.

“Doubts are there. I’m always going to be afraid. Are you going to win or lose – are you going to be humiliated?” said GSP.

“He has self-doubt all the time. His fear of losing is very big. That fear made him excel,” noted GSP’s long-time friend and manager, Rodolphe Beaulieu.

His obsessive state of self-improvement has driven GSP to evolve his training, evolve himself, and evolve his mind.

“It’s so stressful. But I like to win more than I hate to lose.”

That drive may yet cement GSP’s place as the best MMA fighter of all-time.