If you're early on in your career and they give you a choice between a great mentor or higher pay, take the mentor every time. It's not even close. And don't even think about leaving that mentor until your learning curve peaks.

With my business, the way you make big money is you find a great management team and a good concept, and you stick to it, and you add to it over time. In philanthropy, there was more this idea that once an idea was formulated, you moved along.

I love being around kids. I couldn't figure out why all these 70-year-olds wanted to hang out with me when I was 27. Now I understand, and I'm trying to steal their energy from them like they stole from me at the time.

I don't put Tesla in the Amazon category. They have not proved to me that, as a financial model and an economic model, it is going to work.