Sure, it's important to get good grades. Kids with better grades have more options. They get into better colleges and grad schools and then make their way to good jobs. And because grades are all that a kid has to show when first entering the workforce, it’s helpful to do well in school. It’s evidence, too, that the person is likely to duplicate those efforts in the workplace.
Not everyone has the best education, and it doesn't matter.
Not everyone does well academically and not everyone goes to college. I have a friend, now a successful attorney, who got Cs and Ds in high school but who later got his act together to go to law school. A long time client of mine owns a 70-person company and four patents yet never attended college. One friend is a high-level executive for a professional sports team--and commuted to a local state school. The guy who owns my neighborhood pizza shop, as well as two other pizza shops, emigrated from Greece 20 years ago and never finished high school. The successful VP of Sales at another client dropped out of college after two years and went into the military.
Other factors contribute to success.
The people I know who’ve succeeded in business are hard working, they have a positive attitude, and they have passion. They’re optimistic. They do what they say they’re going to do. They are trustworthy, honest, dependable, focused, and smart.
Just not necessarily academically smart. The successful entrepreneur has a sense of profit. An understanding of how to make a buck. An innate enjoyment in taking a dollar and turning it into ten. The business itself often doesn’t even matter. You may have gotten Cs in high school, but you’re the guy who’s calculating the profit and loss that the cruise ship company is making instead of just enjoying your vacation. You’re the person scheming around different and better ways to cook an egg, deliver furniture, or fix a computer--and figuring out how to make money from those ideas. That’s how your mind works. You don’t know anything about the Pythagorean theorem or who won the Napoleonic Wars.
What comes naturally may be golfing with customers and talking about the next order of silicon-coated paper. Or calculating that if you quote an extra ten cents per pound on that pallet of materials you can net an extra five hundred bucks. Or showing up on a bleak January morning with a fist pump and a joke that makes your customer service people chuckle.
You don’t learn this stuff in a classroom.
Some people never learn this at all because they spend too much time in a classroom. Business is all about people. And the most successful business people I know are the ones who understand people the best.