Professionals are generally those who are better at what they do; it's not always by some ginormous or other-worldly amount skill than others, but they are by definition the best at what they do.
Once anyone has a lot of practice, training, education, discipline, and experience, they could probably function at 90-97% of a professional at nearly anything, given enough time, and without regard to any physical or emotional limitations.
That last 3% is what separates the rest of us, and that's why we watch them perform their sport: The percentile increases, and the rest of us can't compete with them on this level. The 97th percentile is normally quite awesome, but compared to his peers, he's quite ordinary.
The 98th percentile is pretty damn good on his or her day, but usually the average one...might be a local favorite, but on a national or international scale...they aren't well-known.
That 99th percentile...they are some of the best around at whatever they do. They're well known outside their realm, they are respected outside their circles, and they command whatever dollar they ask for their services.
And then there's the very few who seemingly transcend their career, their sport, their livelihoods and become icons, coined words, household names...they are legends that are still respected long after they've retired or passed on.
So a professional racing driver just happens to be that much quicker than anyone else; it might look easy, but they have the right mix of talent, skill, bravery, knowledge, and in some cases, "right opportunity" to make it happen. Someone on the back of a Formula One grid would usually be a top-notch driver at the next step down, and when that car is barely qualifying at 7% slower than the fastest guy out on the track, he still has buckets more talent than you or I have, without the requisite experience.
Players, drivers, professionals make mistakes, and our emotions carry us away when we say "He's an idiot...I could do that...I wouldn't have made that mistake." Boloney...you're not in his shoes, with the same pressure and spotlight on you, controlling a 800-horsepower missile around a track isn't easy until you've been there.
Nearly every racing driver is an athlete; the fitness of keeping up with the physical demands of driving a car at it's limits, without air conditioning, with high body temperature, a high heart rate, and with the mental will and discipline to control all the external surroundings, the immediate moment, understanding the limits of the machinery, following the rules, and keeping one's internal demands at bay is definitely something that requires a fitness that many people are completely unaware of.
Oh yeah, motor racing is dangerous, on top of all that. You're only as good as your last performance. Sponsors are waiting. This puts food on the table (or more yachts in the harbor). Ignore that little voice telling you otherwise. Try to keep all that out of your head at the same time.