Amazon CEO: An 'embarrassing' amount of your success depends on this one skill

The trick to getting ahead at work isn't being the fastest learner or the smartest in the room — it's having a positive attitude, says Amazon CEO Andy Jassy.

Jassy, who took the top job at Amazon after Jeff Bezos stepped down in 2021, shared his "best career advice" in a new interview with LinkedIn CEO Ryan Roslansky. 

"I think an embarrassing amount of how well you do, particularly in your 20s, has to do with attitude," Jassy, 56, said. 

It's not just about being cheerful, he explained. Having a positive attitude means you work well on a team and honor deadlines, among other strengths. 

If you have the right mindset, Jassy said you should be able to confidently answer "yes" to the following questions: 

These strategies are "so simple" and yet often overlooked, he said. 

"People would be surprised [at] how infrequently people have great attitudes," he added. "I think it makes a big difference."

Enthusiasm can enable you to take advantage of opportunities like stretch assignments and training programs because you'll feel more confident stepping out of your comfort zone and trust that you can tackle any challenges that arise.

Jassy was just 29 when he joined Amazon as a marketing manager in 1997. Five years into his career there, he was invited to be Bezos's first "shadow" advisor, a quasi-chief of staff who joins all of the CEO's meetings. 

Several of his colleagues at Amazon told him not to accept the offer, but Jassy said he chose to focus on the positive aspects of the job — and by taking it, he was able to strengthen his leadership skills. 

"I just figured if it wasn't something that worked out either for Jeff or for me if I tried it a few months, I could always try something else, but if it did work out, I hadn't ever heard of another job like this," he said. "And it was just an incredible experience." 

It's important to note that Amazon's leadership has come under fire for its treatment of warehouse employees during the Covid-19 pandemic and for allegedly fostering a harsh workplace culture.

Jassy has previously acknowledged that the company could improve its treatment of employees. "I think if you have a large group of people like we do … it's almost like a small country," he said during the GeekWire Summit in 2021. "There are lots of things you could do better."

Regardless of where you're at in your career, having a positive attitude can help you build stronger relationships in the workplace. "You pick up advocates and mentors much more quickly," Jassy said. "People want those people to succeed."

Research has affirmed the benefits of a positive attitude in the workplace — that it can make you more productive, boost creativity and prevent burnout, among other advantages.

"There's so many things that you can't control in your work life," Jassy said. "But you can control your attitude."

Want to land your dream job in 2024? Take CNBC's new online course How to Ace Your Job Interview to learn what hiring managers are really looking for, body language techniques, what to say and not to say, and the best way to talk about pay. Use discount code NEWGRAD to get 50% off from 5/1/24 to 6/30/24.

Plus, sign up for CNBC Make It's newsletter to get tips and tricks for success at work, with money and in life.