Do what you love and the money will follow.

This kind of advice has been passed down from generation to generation. Parents have been telling their children to follow their passions if they want to be successful. And anyone who has attended a graduation ceremony has probably heard some version of this from the commencement speaker.

“The only way to do great work is to love what you do. If you haven’t found it yet, keep looking. Don’t settle.” –Steve Jobs

But I’ve never actually bought into it.

I grew up a science buff with my very own basement laboratory equipped with beakers, test tubes, and rows of powdery chemicals in labeled bottles. Most of the chemicals were harmless, but in today’s world some would make even the most lenient parent worry.

Just thinking about it now brings back memories of how I dreamed of discovering a cure for all diseases, generating pungent odors and mini explosions as I put fire to assorted noxious mixtures.

I was so into playing mad scientist that I almost burned down my parent’s house. Fed by sci-fi movies and television, and wanting to act like a “real” scientist, I ditched the alcohol lamp that came with a Gilbert chemistry set I got for Christmas and purchased a Bunsen burner with my allowance. The sooty flame set a table made from wooden crates afire when I tried to attach the burner to the fuel tank of a Coleman stove intended for camping. What was I thinking?

But all that mad scientist stuff came to an end when I hit my mid teens, and increasing regulations and safety concerns brought an end to the chemistry set. While I still dreamed of being a scientist one day, conversations around the dinner table centered on business, with my father a corporate executive. Those conversations influenced me, either intentionally or not, to study economics rather than science when I entered college.

It’s been 50 years since I set that crate-table on fire. And even though I’ve had a great business career, my passion remains science. That’s why I spend a lot of time thinking about it. Not only do I read scientific writing, I also write myself whenever possible.

In fact, I’ve published several science-related stories here on Thrive Global—including one about recent research that suggests the chilling possibility that our brains are working as much as 10 minutes after we die. The very though of knowing that you’re dead sounds like something right out of a Vincent Price/Boris Karloff movie, two of my favorite Hollywood scientists who didn’t believe in moderation in their craziness.

At this point, if you’re still reading, you probably wonder if I should have made a career 180 years ago. I’ve asked myself that question and the answer is no.

Despite my fascination with chemistry sets as a child, somewhere along the way my passion for science switched from chemistry to physics. I’m totally fascinated today with anything having to do with wormholes, parallel universes, and most of all, the concept of time. And that’s where physics comes in. Physics is the only science that explicitly studies time.

So why didn’t I make a career shift—from analyzing demand and supply curves to studying what Einstein meant about the idea of relativistic time when he wrote, “For us believing physicists, the distinction between past, present and future is only a stubbornly persistent illusion?”

Well, because physics is very math intensive and Einstein’s equations are way over my head.

When you stop and think about it, being excited about what you do is important, but it’s just part of the formula. You must also be gifted — after all, most music reality show contestants passionate about music don’t become singers.

Take American Idol. Through 15 seasons, the show provided big breaks for stars such as Kelly Clarkson, Carrie Underwood, and more. But along with the winners, there were hundreds who didn’t get past the first round despite having interest in music as a child. Even some who took home the top prize, like Lee DeWyze and Nick Fradiani, didn’t hit the big time.

So while we’ve all heard the saying, “follow your passion,” actually doing it might not lead to success. In fact, most people don’t have childhood passions that can be easily matched to their career. As a science-buff-turned-economist, I know what I’m talking about.

You’ve probably heard somewhere before that having exceptional math skills is important in the field of physics. I’m not implying that I stink at math because I don’t. I took the required statistics and calculus classes while studying economics in grad school, and a few courses beyond that. Graduate level coursework in economics actually involves not just theory but a great deal of math, particularly complex algebraic formulas and statistics. In fact, the math is so deep that some students label economics as one of the hardest college classes.

But economics math is child’s play compared to physics math. In fact, physics is the most mathematical of the sciences and if you’re going to make it a career, you need an amount of mathematical knowledge far greater than I have. We’re talking advanced differential equations to study optics, advanced liner algebra to master quantum mechanics, and advanced differential geometry if you go into gravity and relativity.

Just thinking about those courses makes me shiver. They are infamous for being some of the hardest classes you can take, and they weed out the physicists from the wannabes like me. If there were a textbook example of someone inept in physics-level math, I’d be Exhibit A.

For those reading this piece who honestly believe you can be anything you want and be successful, I give you this as an example: I love to run and I was a record holder in college. But as much as I dreamed about it, no amount of training was going to make me good enough to run a sub four-minute mile. I simply did not have the heart and lung capacity. It’s no different with physics.

“One of the great lies of life is follow your passion.” –Mark Cuban

There is an intimate relationship between mathematic and physics, and if you want to be a physicist, it is necessary to understand the language that physics speaks in. As much as I want it, no amount of studying can help me acquire something so heavily abstract and overwhelming—just like I couldn’t break four minutes in the mile despite how hard I trained.

The point is, you can’t just master something by loving it. Being proficient comes through sweat and tears, and more than that, having ability. Do you think you could become the next Michael Phelps just because you love swimming and train like an Olympian? Probably not. The same is true for everything in life. Not all of us can write music and paint.

So even though it’s been said many times, doing what you love is bad career advice. In fact, according to Stanford University researchers, that advice may actually make you less successful. Even Steve Jobs didn’t follow his own advice. If he had followed his decades-long passion, he would have become a Zen master. Instead he made iPhones and Mac computers.