The bigger you get, the harder this gets because the more aggressive the people working for you are.

Leadership is hard to train on.

I was an executive running a pretty substantial group before becoming CEO, and I had no idea what it was like. When something goes wrong, people say, 'It's all your fault.' Your reaction is, 'It's not my fault.' But what do you mean? I was the founder, I hired everybody in the company, I was managing it.

Over the last ten years, technological advances have dramatically lowered the financial bar for starting a new company, but the courage bar for building a great company remains as high as it has ever been.

The thing that's confusing for investors is that founders don't know how to be CEO. I didn't know how to do the job when I was a CEO. Founder CEOs don't know how to be CEOs, but it doesn't mean they can't learn. The question is... can the founder learn that job and can they tolerate all mistakes they will make doing it?

Groupon looked like a very high valuation, but any investment in a great company at any stage is almost always a good investment.

The person they're working with, is going to be the person they'll know more. So if that person leaves, they're going to go - well, should have I left too? What did they get and how does that compare to my deal.