On my 10th birthday, my dad, a dairy farmer, scrambled together enough money to buy me a horse. I’d been pleading for a pony, but I think he figured getting me a full brown horse, albeit it one that was very long in the tooth, would allow me to get a little bit more use out of him.

I remember looking up at him, 14 hands high, and feeling very intimidated. Wow. How was I ever going to get all the way up there? How was I ever going to learn to ride such a big horse? But I was determined to figure it out, and so every morning before going off to school, I’d head out to the paddock and saddle him up.

In the beginning, I was quite terrified, but over time, I became more confident and eventually became the local barrel-racing queen (well, I like to think I was anyway). Those years of learning to ride my first horse, and then later my second (which we won in a raffle!), taught me some valuable lessons for life. The first and most important was that growth and comfort can’t ride the same horse.

Ginny Rometty, CEO of IBM, said something similar while reflecting on her own career: “Growth and comfort do not coexist.” Whether you’re stepping into a bigger role at work, learning a new skill, pursuing a goal or making a change, you can’t grow into the person you want to be unless you’re first willing to get uncomfortable.

Related: Why Stepping Outside Your Comfort Zone Is Worth It—Even When It’s Uncomfortable

Since my childhood growing up in rural Australia, I’ve taken countless steps outside my comfort zone. Each one has reinforced the universal truth, that what we yearn for most often lies on the other side of what scares us most. It requires allowing ourselves to be vulnerable to rejection, to losing face or falling short.

“Life’s magic happens outside your comfort zone” may be a popular catchphrase, but that does not negate its truth. Which begs the question: Why do so many people tiptoe through life, spending their best years in the confines of a shrinking comfort zone?

The answer is simple.

We’re wired for safety, security and social approval, not for risking it. We may live in modern, urban times, but we still inhabit brains that were wired for long ago, when not being hyper-alert to potential threats led to certain death.

This is why in today’s 24/7 culture of fear, we must be extra vigilant to keep our innate desire to protect ourselves from situations that make us feel uncomfortable from keeping us from stepping into situations that will enable us to grow. Because you know what else? Comfort doesn’t stay comfortable forever. Sticking with the comfort of the status quo may provide a short-term sense of security, but spend too much time in your comfort zone and your muscles for life will gradually wither.

All too often, I encounter people who’ve lost all confidence in themselves because each time they’ve had the choice to do the brave thing over the easy thing, they’ve opted for the latter. In the process, they’ve inadvertently deprived themselves of opportunities to learn new skills, cultivate their talents, hone their strengths, expand their capacity, reinforce their value and build their “muscles for life.”

Take a moment to think of what you are most proud of in your life to date. I’ll guarantee you that it won’t be something that was easy or didn’t stretch you. In fact, it’s likely something that challenged and stretched you in many new ways. That’s how life works. We don’t grow from the times life is easy and everything goes according to plan. Rather, we grow when we are stretched, when we have to adapt to change or we’re thrown a curveball that requires us to dig deep. I mean, just imagine the growth you’d have missed out on had everything you’d ever done or wanted gone exactly to plan? Certainly not half the person you are!

Likewise, if you look ahead to the future, I can guarantee that achieving what you want most and creating a life that is rich in meaning, connection and contribution will require you to choose growth over comfort and trade the safety of the familiar for the uncertainty of the new.

To embolden you to embrace discomfort as a prerequisite for real success, I encourage you to create a vision for your future that really inspires you—one that connects you to a cause bigger than protecting your ego or social approval. Too often our ego’s desire to look good keeps us from doing good!

Leaving your comfort zone requires courage. So unless you’re clear about why you need to put yourself “out there” where the fainthearted don’t dare to go, you’ll never ever accomplish what you’re capable of doing—and what the world needs you to do—and you are guaranteed to go to your grave with the song still in you.

And if there’s one thing I know for sure, it’s that you don’t want to do that.

Nelson Mandela once said, “There is no passion to be found playing small—in settling for a life that is less than the one you are capable of living.”

You know in your heart of hearts where you’ve been settling, selling yourself short and, in the process, cutting yourself off from the possibilities that inspire you most deeply.

As I wrote in Brave, it is never too late to become the person you most aspire to become. So take a deep breath—inhale faith, exhale fear—and connect with that bold vision that tugs at your heart, however daunting the gap it creates between where you are now and where you want to be.

Then make the brave decision that the time has come for you to take your first bold step toward the biggest future you have imagined, however far off the beaten and comfortable path that may take you.

Trust yourself, and have faith that you have everything—and I mean everything—it takes to meet whatever challenges arise on the path ahead.

Magic awaits.

Related: 52+ Ways to Get Out of Your Comfort Zone