Forty-five years after Apple’s IPO, the company is now worth $4.1 trillion—but its rise was anything but smooth. Steve Jobs weathered near-bankruptcy and was even ousted from the company he had built, before returning and setting the stage for Apple’s resurgence. But what kept him going, he once told students, was a simple career lesson: Doing the work you love.“Your work is going to fill a large part of your life, and the only way to be truly satisfied is to do what you believe is great work. And the only way to do great work is to love what you do,” Jobs said during his 2005 Stanford Commencement speech. “If you haven’t found it yet, keep looking—and don’t settle. As with all matters of the heart, you’ll know when you find it.”Many Gen Zers are apprehensive about what career to choose. Some are taking whatever gig they can get in today’s labor market, as roles are quickly being disrupted by AI, and once-lucrative jobs have fallen out of favor. But Jobs’ story is a reminder to young professionals that chasing a long, passionate career in what they love is the recipe for sustainable success. After all, they have a nearly 50-year career ahead of them.The many jobs that Steve Jobs had and lovedJobs’ has a diverse lineup of successful ventures under his belt—including Pixar Animation Studios, and software company NeXT—but Apple was his ultimate brainchild. Leading the company through its many iterations, Jobs helmed the creation of generation-defining products for decades. Baby boomers waited in line to snag the Apple II computer back in 1977; by 2001, millennials were flooding their music collections onto the iPod classic; and all throughout the 2010s, Gen Zers were gifted their first iPhones.Apple may seem like an unmovable force today, sitting at number four on the Fortune 500 and having sold more than three billion iPhones. But its come-up was anything but sunshines and rainbows; despite cofounding the titan of industry, Jobs was forced out by then-CEO John Sculley in 1985, throwing his career into flux. The entrepreneur recalled making the most of the bad situation, entering one of the “most creative periods” of his life by launching NeXT and revamping Pixar Studios. But even he couldn’t resist the gravitational pull back to the “best thing that ever happened to [him],” Apple. He returned to the fledgling company as CEO in 1997, and remained in the role until just two months before his passing in October 2011. “Sometimes life hits you in the head with a brick. Don’t lose faith,” Jobs said. “I’m convinced that the only thing that kept me going was that I loved what I did. You’ve got to find what you love.”Jobs’ love for his work turned him into a billionaireDespite leaving behind a fortune estimated to be worth $10.2 billion at the time of his passing, Jobs made it clear that his ambitions weren’t tied to his bank account. A part of why Apple became a trillion-dollar innovator may be thanks to his devotion for the products—a life-long love for technology he first discovered as an eager tween, hungry for opportunity. “I was worth about over $1 million when I was 23, and over $10 million when I was 24, and over $100 million when I was 25,” Jobs told PBS in 1996. “And it wasn’t that important, because I never did it for the money.”The iPhones sitting in millions of back pockets and MacBooks scattered across swaths of desks may not even exist if it weren’t for Jobs’ devotion to the craft. At just 12 years old, he took a leap of faith to put his passion into action; Jobs hunted down the phone number of the founder of Hewlett Packard (HP) cofounder Bill Hewlett’s in the yellow pages, and called him up for a favor. The tween needed spare parts needed to build a frequency counter, but he got far more than some nuts and bolts. Hewlett offered Jobs a gig at the iconic tech company—a launchpad for his future successes dominating the same industry. Jobs set himself on the path for greatness, all because he mustered the courage to try. “I never found anybody that didn’t want to help me if I asked them for help. I always call them up,” Jobs said in a 1994 interview, archived by the Silicon Valley Historical Association. “I’ve never found anyone who says ‘no,’ or hung up the phone when I called. I just asked.”“Most people never pick up the phone and call. Most people never ask…You’ve got to be willing to crash and burn with people on the phone, with starting a company, with whatever. If you’re afraid of failing, you won’t get very far.”This story was originally featured on Fortune.com