Say ‘yes’ to every opportunity if you want to advance your career, says former Walgreens CEO

It can be hard to say "yes" to new opportunities, especially if they pull you out of your comfort zone. But agreeing to, or even strongly considering, every opportunity that comes your way is crucial to advancing your career.

Greg Wasson, former CEO of Walgreens, tells CNBC Make It that he became the pharmacy chain's top exec by taking on every new role that was presented to him.

"You learn so much with each new role," says Wasson, who worked at the retail pharmacy company for 34 years. "It's always an opportunity to learn."

The former CEO started at the health chain as an intern, while he was a pharmacy student, before eventually managing a Walgreens drugstore.

He was promoted to district manager and soon became the company's regional vice president. He was then given the opportunity to run all of Walgreens' health services, which "did everything non-drugstore related," before becoming the chain's COO and ultimately its CEO in 2009.

Each role brought him to a new region in the U.S. and also challenged his thinking, which "kept it new and exciting," says Wasson. He adds, "I wanted to do the best I could in every position. I was highly competitive." And his bosses took note.

Wasson says that his higher-ups saw his hard work and rewarded him with new opportunities, which helped rapidly advance his career. But he admits it wasn't easy always saying "yes." When he was asked to run Walgreens' health services he says he "really had to think about it" because he had "no idea what was coming [his] way."

Wasson accepted the job, which took him to Las Vegas, and it ended up being the single most important role in launching his career into upper management.

"I took the role because I thought it would be an opportunity to learn," he says. "An opportunity I thought was crazy ended up being very important in my career."

Wasson suggests looking at two key things when faced with a new opportunity: its impact on your quality of life and the timing. Then ask yourself, "What can the opportunity do for me?"

The CEO says that new opportunities broaden your experience and also provide great exposure to other people within an organization.

"Anytime you can broaden your base either at a company or outside of it is beneficial," says Wasson.

He adds: "The opportunity to broaden your knowledge and expertise is of value as you move up in your career. So at least strongly consider every opportunity that comes your way because it may end up being the most important."