Can a professional race car driver start off racing motorcycles?

I'm 14 I hope to become a professional motorist one day

Like INDYCAR, Formula One, NASCAR, etc.

And I know most of those guys start off by racing Go-Karts

But, personally I'm not a big fan of Go-Karts, they don't feel like a real car.

I like motorcycles, and yes I know how to ride them.

Is it possible to start of racing motorcycles and then later on hope to get noticed and sponsored and make a transition to cars.

I can get like a Honda and take it to the track
And then transition to something like a Ducati when I get older and I get sponsors
And then I make the transition to automobiles

Although I'm not sure weather to get a sport bike/street bike or a dirt bike.
It seems like most youth completions are for dirt bikes and not sport bikes, but I'm not sure on that.

http://powersports.honda.com/...r250r.aspx

http://powersports.honda.com/...treet.aspx

http://powersports.honda.com/...treet.aspx

You think that a kart doesn't feel like a car?

What do you think an actual race car handles like? The kart is closer than 99% of the street cars out there and teaches you the skills needed to be a competitive driver.

You are already 5+ years behind the kids currently racing mx, going to be tough trying to play catch-up.

You really think its this easy to race bikes?

You are living in a dream world mate. Where does the money come from?

Also, Damon Hill & Colin MacRea both started off racing motorbikes before going car racing.