Susan Cain

Shyness is about the fear of social judgments - at a job interview or a party you might be excessively worried about what people think of you. Whereas an introvert might not feel any of those things at all, they simply have the preference to be in a quieter setting.

The thing about dancing - what it taught me all those years - is it gives you an amazing sense of discipline in forcing yourself to do things that you know are good for you but you don't really want to do.