This is what General Electric (GE) CEO Jeff Immelt said when I asked him the following question on The Chat, Fortune‘s new video interview show: What is the most important trait for a leader to be successful today?

“If you want to be successful, you’ve got to have an antenna up all the time, and you’ve got to be open to new ideas,” said Immelt, whose company ranks No. 8 on the 2015 Fortune 500.

“You’ve got to be grabbing every new thought you can come up with,” he explained. “And you can never feel like you’re safe in anything you do.”

Immelt’s answer reminds me of the reply I recall Jack Welch, his predecessor, giving to the same question before he handed over the CEO job at GE in 2001. “Curiosity,” Welch said, is an essential ingredient of great leadership.

The lesson for bosses in the Fortune 500 and anyone else striving to get there? As the world changes at an increasingly fast pace, learning will always be what you need most to succeed.

Watch Fortune‘s Leigh Gallagher, Geoff Colvin, and me talk about leadership traits and lessons from the Fortune 500 on Fortune Live today at 3 p.m. on Fortune.com.