Everyone was a grom once - even Kelly Slater and Shaun White.
It's hard to picture, right? When you've grown up tracing the careers of these action sports "superstars", it is almost impossible to imagine a time when they weren't dominating the best waves, dirt tracks, pipes and bowls in the world.
Like a warped version of It's A Wonderful Life, sometimes it is strange to consider a surf, skate, snowboard or moto scene where the pillars of the sport didn't exist.
Who would have been the first snowboarder to lay down a back-to-back double cork in the superpipe? Would any surfer have managed to dominate the WCT for over 20 years?
But the legends do exist - and action sports are all the better for it. Even at nine-year-old, it seems these guys were already stars in the making.
Stacy Peralta was one of those tiny groms that make you feel ancient just watching him ride. Travis Pastrana was already building jumps in his backyard.
So, which action stars' pasts have we delved into for a quick peek? Click through our yearbook-style slidereel and find out...
[part title="Kelly Slater"]
He's arguably the best surfer that ever lived, so it won't come as a shock to hear that Kelly Slater started surfing at the age of 5. He doesn't look too much older than that here!
There's a tonne of amazing old-skool footage of Slater's early days out there - from his nine Baywatch appearances to being voted one of People magazine's 100 Most Beautiful People in the World in 1991.
Interesting fact of the day: he's both the youngest and the oldest world champion in ASP history - he won his first world title aged 20 in 1992 and his latest aged 39 in 2011!
[part title="Tony Hawk"]
World famous Tony Hawk started life as a "thin, gangly hyperactive kid" with a fiercely competitive attitude. His parents encouraged his skateboarding use up his excess energy as a kid.
Rumour has it, Hawk had to ollie into aerial manoeuvres to give them a try because he was so small! Still, it turned out alright for him in the end.
[part title="Terje Haakonsen"]
The legendary Terje Haakonsen only started riding aged 13 when he borrowed his neighbour's Burton Elite 150 and hiked through farm hills in Norway to try it out.
Before he knew it, he was winning European cups, leaving school aged 15 and signing to Burton.
Just check out the interview with 17-year-old Terje below from 1991 shred movie Scream of Consciousness. His answers are priceless and his riding style equally so.
[part title="Travis Pastrana"]
They say you should start them young. For motorsports champ Travis Pastrana that meant mounting a Honda one-speed aged four and building jumps in his backyard.
Even as a kid, his love of riding was unparalleled. Childhood friend Jim DeChamp once said: "I would go ride [in Travis' backyard] before school. I’d get back after school, he would have built new, bigger jumps. By the time I got off school the next day it would be 3 feet longer."
It's not surprising that he was only 16-years-old when he won the first ever gold at the X Games Moto X Freestyle event.
[part title="Lisa Andersen"]
Four-time world surfing champion Lisa Andersen started surfing aged 13 when her family moved from New York state to Florida. Unfortunately, her family weren't so supportive of her riding, blaming the sport for her bunking off school and slacking on grades.
This photo (above) was taken just before she ran away from home aged 16, leaving her mum a note saying she was running away to be a women's world champion surfer - and never came back.
[part title="Stacy Peralta"]
Stacy Peralta started skating aged 5 when JFK was still the US president and hardly anyone knew who The Beatles were.
By the time he was 11, Stacy was a professional skateboarder at a time when the concept was laughable. Skateboarding was just another fad, like yoyos and pogo sticks.
"Our parents didn't pay attention to our skateboarding. At the time it was considered such a trivial thing to do," Peralta told Californian TV station KCET in an interview. How wrong they were.
[part title="Shaun White"]
Now here's a face you'd recognise from a mile off. The Flying Tomato was living up to his barnet-inspired namesake even as a little kid.
It probably won't surprise you to learn that Shaun entered his first snowboard comp aged seven... and won it. Obviously.
By the time he was eight-years-old, he was already executing airs in the pipe, a good four foot higher than the other kids.
Intrigued to see just how good he actually was? Watch the video footage below of Shaun ripping aged 10!