A plane is a guilty pleasure. I have one. It's a great luxury. I appreciate it. I couldn't do what I do. It's not something you can write down as anything other than, "Wow, I can't believe I have this and I'm absolutely spoiled and entitled." On the other hand, I have one and I use it.

From a client perspective, I really think the work Microsoft's doing with Surface, with HoloLens, with Xbox, that stuff's absolutely essential to the company's future. Because innovation in the future will either be from the cloud out to all devices, or from devices as supported by software in the cloud. I think it's important for Microsoft to participate both ways.

Any idea that turns out to be truly great can be harvested for tens of years. On the other hand, if you want to continue to be great, you've got to bet on new things, big, bold bets.

Almost three years ago, when I retired, my wife and I were talking about our philanthropic work and how does one help give opportunity, particularly to kids growing up in very disadvantaged situations.And my initial kind of sense was, the government does that primarily, and what we should mostly do is pay our taxes. My wife said, no, I don't think that's quite right for us. We need to do more. We can do better.

When you're running a company, you have employees - lots of them - that can interrupt your schedule. You have customers that can interrupt your schedule. You have a certain obligation to wave the flag because people expect to get out and wave the flag. The number of ways that others can command your time is high. At this stage, I get to pick and choose a little more. Not that there aren't some things that have to be done, but I get a little more control over my time.

I meet with Satya [Nadella] what probably amounts to four or five times a year - either to brainstorm something or just as a shareholder, we'll sit down and chat. That's always quite helpful for me and hopefully him in terms of thinking things through. I still have a number of friends and colleagues who occasionally want to brainstorm or chat about something, and that's always fun.

I'm very, very bullish about our prospects, and as I tell our board, as I tell our employees, this is the time to invest. There's so much opportunity. Let's just invest in that opportunity, and really get after it.