Don’t get us wrong: Education is certainly important.

In order to be successful, you need to know how the world works, and decent grades correlate with success, as far as we know. If you’re a straight- A student, you should have a relatively stable financial life, right?

Not necessarily. As Paul Kimelman writes for Freakonomics, scientific studies that compare success with school performance are deeply flawed for several reasons. Defining success is difficult, and because universities are biased in favor of education, it’s difficult to come up with objective information.

That doesn’t downplay the importance of education, but it does bring up an important question: Why do we assume that straight-A students are better equipped for their adult lives than straight-C students?

You don’t have to look very hard to find successful straight-C students.

“To those of you who are graduating this afternoon with high honors, awards and distinctions, I say, ‘Well done,'” the former President said. “And as I like to tell the C students: You too, can be president.”

At the time, the moment was reported as a funny, self-effacing aside, but it’s true. Facebook founder Mark Zuckerberg regularly skipped classes before dropping out of Harvard. Steve Jobs of Apple dropped out of college at 19. Bill Gates, founder of Microsoft, dropped out at 20.

The list goes on; Dell founder Michael Dell, Wikileaks founder Julian Assange, Uber founder Travis Kalanik, and Whole Foods founder John Mackey all dropped out of college. All of those entrepreneurs went on to have wildly successful lives. What gives?

Average students may have one major advantage over their perfect-GPA colleagues.

They know exactly what they want, and they’re willing to focus entirely on their goals.

An anecdote from Funders and Founders puts this into perspective. Mark Zuckerberg was interviewing a Stanford student for a position at Facebook when he reportedly asked a pointed question:

“Why would you be studying it if you could be doing it?”

It’s a bafflingly straightforward question, and it exposes a potential issue with the American approach to education. Specialization allows for results; general education can slow down someone who’s ready to start their professional life.

Google’s head of people operations, Laszlo Bock, told the New York Times that his company looks past GPAs when hiring.

“The No. 1 thing we look for is general cognitive ability, and it’s not I.Q.,” Bock explains, “It’s learning ability. It’s the ability to process on the fly. It’s the ability to pull together disparate bits of information. We assess that using structured behavioral interviews that we validate to make sure they’re predictive.”

Bock adds that a high GPA isn’t a disqualifying factor; employers still see good grades as a positive. However, GPA isn’t the sole indicator of a worker’s value—just as it isn’t the sole indicator of a person’s capabilities.

Once again, we’d like to emphasize that education is important. It’s just that maybe—just maybe—the grades don’t matter as much as we’d like to think.