Dwayne 'The Rock' Johnson has revealed why he retired from WWE in 2004, at the age of 32. 

The Great One did another Instagram Q&A on Monday and was asked why he chose to walk away from professional wrestling.

He explained that there were two main reasons.  

"I retired in from the WWE in 2004 at the age of 32," The Rock said.

"And at that time, well here's the why. Why I retired was two reasons.

"One: my contract had expired and two: which is the most important thing, an agreement that I have with anybody in the world.

"Any company, any individual, it's always important to me - it means everything to me - to shake that person's hand and look them in the eye.

"In 2004 when my contract expired, I had delivered on my agreement with the WWE and with my long-time mentor and very, very good friend Vince McMahon. 

Rock walked away from WWE on good terms

"We shook hands, that's the way we are."

Rock also added that he retired from WWE as pro wrestling's 'number one draw' and that allowed him to quietly walk away.

"The risk was two-fold. I retired on top as pro wrestling’s #1 draw," he wrote on Instagram, captioning the video. 

The Rock remains WWE's number one draw

"And coming from the world of wrestling, the odds were stacked against me of having a Hollywood career that had any kind of long term, substantial global influence and value.

"After a bewildering seven-year career as a wrestler, I kept my handshake bond - finished out my contractual obligations and quietly retired." 

Despite retiring in 2004, Rock has made numerous appearances in WWE since. 

His return in 2012 set the wrestling world alight again and of course, that match against John Cena at WrestleMania XXVIII broke multiple records. 

Rock vs Cena broke pro wresting records

Many fans will think Rock's original seven-year run in WWE was far too short, but as the man himself says - he retired on top and will always draw the biggest crowds whenever he does return. 

Arguably, that's a perfect career.