David McCullough

I usually feel like the role comes to you to sort of illuminate some piece of where you are in your life. I feel like I myself am a single woman and I'm childless - by choice - at this point, and I don't know what will happen.

And I think that still is true of this business - which is basically research and development - that you probably spend more time in planning and training and designing for things to go wrong, and how you cope with them, than you do for things to go right.