Padmasree Warrior, Cisco's chief technology officer, was asked by The Huffington Post, "What's the most important lesson you've learned from a mistake you've made in the past?" "I said no to a lot of opportunities when I was just starting out because I thought, 'That's not what my degree is in' or 'I don't know about that domain.' In retrospect, at a certain point it's your ability to learn quickly and contribute quickly that matters. One of the things I tell people these days is that there is no perfect fit when you're looking for the next big thing to do. You have to take opportunities and make an opportunity fit for you, rather than the other way around. The ability to learn is the most important quality a leader can have.