Every weekend was dominated by racing, with his family putting in every penny they could to help him reach the top.

Those pennies certainly paid off.

With six wins already this season, 2019 is shaping up to be his best year ever - quite an achievement when you've already won five world titles.

And as he comes home for the 2019 British Grand Prix, Lewis has told Radio 1 Newsbeat that self-belief has helped turn his dreams into reality.

Hamilton and his Mercedes have been called one of the greatest car and driver combinations ever seen

So what would a 12-year-old, squeaky-voiced, kart-racing Lewis Hamilton have said if someone had told him he'd go to the British Grand Prix more than 30 points ahead in the driver's championship, while chasing a sixth world title?

"I'd say that's a pretty cool idea! Of course, I could never have predicted those things, but I truly believed in myself so much when I was young," Lewis tells Newsbeat in the Silverstone paddock.

"Kids have this confidence and aura around them, I'd have been like, 'OK, I'm gonna do it'."

Lewis's self-confident style has not always made him the most popular.

He's controversial at times, but his huge success on the track and the way he's embraced the celebrity side of Formula 1 has also meant he's won millions of young fans.

He speaks about those supporters a lot - especially after significant wins - and wants his admirers around the world to share the same self-belief he had growing up.

"I truly believed and knew I was going to get to Formula 1," he says.

"That belief is what's got me to where I am, so I always try to encourage people to hold on to that. Believe in yourself and block out all the negative distractions around you.

"People doubting you, people making comments, whether it's people on social media, at school, in your family or your friendship group. Keep positive people around you and shut out the ones that are the negatives - focus on your dreams."

Lewis is a cool customer, known for not just his love of fast cars, but fashion too

Many F1 fans want to see a tighter battle for the title.

Ferrari were expected to be much closer to Lewis and his Mercedes team this season, but that's not how it's worked out.

His driving has seemingly taken yet another step forward. He's already won six of the first nine races, making very few mistakes along the way and showing supreme speed.

Only a major shock would stop Lewis winning a sixth world title, just one behind the record-breaking Michael Schumacher.

But of course it's not just about Lewis - he says there are around 2,000 people working "flat out" to make the team as good as it can be.

"The guys that are here at race weekends have to deliver from the package that we're given, so there's not a day that anybody here rests until the job is done," he says.

Hamilton and the Silver Arrows is a pairing which will go down in history and the 340,000 fans who will pile in to Silverstone over the course of the race weekend will see one of sport's current great teams.

And the scary thing for their rivals? There's no sign of their dominance ending anytime soon.