Company: IBM
"You always have to do something that puts you in a zone you don't know," Rometty advised the audience at the 2011 Fortune Most Powerful Women Summit , less than a month before she was elected as the successor to IBM's then-CEO Sam Palmisano. "Someone once told me growth and comfort do not coexist. And I think it's a really good thing to remember."
NEXT: Patricia A. Woertz