You know, I'm not a huge fan of the concept of 'passion' when it comes to careers. Instead of trying to answer the daunting question of 'What's your passion?' it's better simply to watch what you do when you've got time of your own and nobody's looking.

Newtonian physics runs into problems at the subatomic level. Down there--in the land of hadrons, quarks, and Schrödinger's cat--things gent freaky. The cool rationality of Isaac Newton gives way to the bizarre unpredictability of Lewis Carroll.

Now it's easy for someone to set up a storefront and reach the entire world in very modest ways. So these technologies that we thought would dis-intermediate traditional sellers gave more people the tools to be sellers. It also changed the balance of power between sellers and buyers.

One source of frustration in the workplace is the frequent mismatch between what people must do and what people can do. When what they must do exceeds their capabilities, the result is anxiety. When what they must do falls short of their capabilities, the result is boredom. But when the match is just right, the results can be glorious. This is the essence of flow.

There's an idea out there that salespeople have actually been obliterated by the Internet, which is just not supported by the facts.

We have this myth that extroverts are better salespeople. As a result, extroverts are more likely to enter sales; extroverts are more likely to get promoted in sales jobs. But if you look at the correlation between extroversion and actual sales performance - that is, how many times the cash register actually rings - the correlation's almost zero.

The ability to take another perspective has become one of the keys to both sales and non-sales selling. And the social science research on perspective-taking yields some important lessons for all of us.