Peter Sagan is a hell of a bike rider. He's a bit of an eccentric, prone to popping wheelies on his uber-expensive road bike, and seems to have more fun than the average ProTour rider. And it doesn't hurt his results (2014 Green Jersey for most points in the Tour de France). Combine that with only being 23, and you have someone who could dominate top-level cycling for a decade or so.
But he also has some serious cojones tucked into that cycling onesie. Watch this descent from the 2014 Tour de Suisse:
I'm not saying that car racers are wimps. But it's one thing to go fast when you're surrounded by the finest safety materials that hundreds of millions of dollars in R&D can fashion; another when your skin's only protection from a bouncy skid along the tarmac at 55 mph is a thin layer of spandex.