If you want to bring a fundamental change in people's belief and behavior...you need to create a community around them, where those new beliefs can be practiced and expressed and nurtured.

If we think about emotion this way - as outside-in, not inside out - it is possible to understand how some people can have an enormous amount of influence over others. Some of us, after all, are very good at expressiing emotions and feelings, which means that we are far more emotionally contagious than the rest of us.

I'm convinced that ideas and behaviors and new products move through a population very much like a disease does.

Insight is not a lightbulb that goes off inside our heads. It is a flickering candle that can easily be snuffed out.

Courage is what you earn when you've been through the tough times and you discover they aren't so tough after all.

There are exceptional people out there who are capable of starting epidemics. All you have to do is find them.

Anyone who has ever scanned the bookshelves of a new girlfriend or boyfriend- or peeked inside his or her medicine cabinet- understands this implicitly; you can learn as much - or more - from one glance at a private space as you can from hours of exposure to a public face.