Kelly Slater’s 11 world titles haven’t come easy, regardless of how they’ve looked. Keeping the drive alive for two full decades involves incredible sacrifice and dedication. Time and again, Slater’s either had to wait patiently or dig deep for new sources of motivation. One year it’s a new threat, the next it’s validating new equipment. And lately, after being pushed by guys half his age, it’s been incorporating a new brand of acrobatic surfing.

Believe it or not, the world’s greatest surfer turns 40 on Saturday, one week before he sets out to defend the same title he first won back in 1992, when he became the youngest world champion ever.

Two decades later he owns every record in the book, and continues to meet every challenge he dares to set in front of him. So what—if anything—could possibly be motivating this man heading into 2012?

Well, aside from winning at 40, how about that little thing we call mankind?

Let’s face it, at this point Slater is a science experiment. A lab specimen if you will. C’mon, no athlete in history has dominated his field as long as Slater. Period. And what’s more remarkable is he keeps getting better. How the hell is this possible? No, seriously? The guy keeps rewriting the rules of endurance and stamina, so why stop now? Why not let man know once and for all what’s physically possible? When will we get another chance like this to learn?

We figured Kelly hitting the big Four-Oh was as good an excuse as any to catch up with him. After welcoming him into the dinosaur club, he revealed some of his secrets for staying young in our probing Q&A where Kelly filled in the blanks. One thing is certain: if you think he’s bummed about getting older, think again.

1.) Dude, haven’t you heard? 40 is the new shit.

2.) I’ve tried a lot of different exercise and workout variations over the years, from yoga to sex, circuit training, the gym and bodysurfing. But right now I’m having the most fun with people thinking I know Jiu Jitsu.

3.) Based on my vitals (blood pressure, cholesterol, body fat, resting heart beat) I’d say my “real age” is probably between 20 and 39.

4.) When I’m not in the water eating healthy and not overeating has helped me stay in shape the most during my career.

5.) I used to eat a lot of sugar, but now I don’t touch it. I’ve basically replaced it with maple syrup or Stevia because it’s healthier.

6.) When I look at 50-year-old guys like Dr. Nick Delgado or Dr. Bob Delmonteque(when he was 90!) I get inspired about the future.

7.) The best thing for me to eat when I wake up on a contest morning is warm water and lemon, then fresh, organic, sub-acid fruits (apples, pears, grapes, etc.) because the cleansing and alkalizing to get your system going.

8.) The food that’s the absolute hardest for me to stay away from is Haagen-Dazs Vanilla Swiss Almond.

Kelly Slater through the years. Top: Quik Pro New York 2011, photo: Kirstin/ASP. Middle row: The wonder years in Florida. Photo: Dugan/Quiksilver; Tavarua takeover. Photo: Serviais/Quiksilver.