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Featured Image Credit: Instagram
In recent years, though, he's lost weight and carved himself a career as a serious actor, moving away from the more puerile humour that made him famous.
Part of this reinvention has seen him gain new confidence, and last year he began learning the popular martial art of Jiu Jitzu.
But if his latest post to social media is anything to go by, it's safe to say he's not top of the class just yet, after he revealed he got his 'ass kicked' by a 12-year-old.
In a post to his Instagram account today, the Wolf on Wall Street star shared a photograph of himself in his full kit, sporting his bleach blond locks.
The picture's caption read: "Nothing more humbling than getting your ass kicked by a 12 year old your first week. Got my first stripe today. I know it sounds corny but it's pretty dope to jump in and do stuff you'd never think you'd be able to do."
The Hollywood A-lister also used the post to open up about his insecurities, which he says have followed him throughout his life, and that he's trying to 'let go' of the things that have been holding him back for so long.
He bravely admitted: "I started Brazilian Jiu Jitzu 2 months ago and try and train 4 or 5 times a week. In high school the dudes who did Jiu Jitzu used to beat the shit out of us at parties so it turned me off to it as an idea growing up.
"But quietly I always thought it was a beautiful art form . At 35 , I try and get over the stuff that made me feel weak and insecure as a teenager. It's just wasted time and lessons you'll never learn. Trying to let go of that."
He added: "Much respect to Sensai Josh and @clockworkbjj and Anthony for getting me into it."
Many fans have been commenting on the post, showing their support for the actor and praising his courage for being so honest.
One person wrote: "Get it! Flipping the script on the negativity and finding peace."
Another said: "So true about the wasted time. Always look forward Jonah!"
A third follower added: "This is truly motivating. Thank you so much for sharing!"
"Welcome Jonah to a beautiful art for the mind and the soul. Great words and thank you for sharing. Respect", wrote another.
Well done, Jonah. A fantastic example to everyone trying to face their own battles.