Every day you spend becoming an expert in a field, you become more useless in that field.

My parents didn't believe in luck. They believed in hard work and in preparing me to take advantage of opportunity. Like many parents, they taught me to be generous but never to depend on the generosity of others.

'Being green' is commendable, but I hope that people don't take too much pride and self-adoration because they shut off the water when they brushed their teeth. The truth of the matter is, conservation alone will do little to save our planet.

The truth is, what Americans enjoy about football is much of what makes the sport dangerous. However, I believe there must be a way to find the art of success and vitality in football, without the driving the level of impact that causes serious risk of head trauma, paralysis and other life-changing injuries.

Once humans traded their hunter-gatherer existences for more settled communities, we began a quest to make our lives better and more comfortable, but we've also been sucking precious finite resources from our environment ever since.

I believe that entrepreneurs play an unmatched role and the accelerating pace of innovation is transforming the face of global challenges. You must think about the solution differently when you're trying to impact 1 billion people rather than affecting 1 million people.

The U.S. has spent billions of dollars on educating and supporting teachers or developing curricula but no resources are applied to 'improving the brain' that a student brings to the classroom.