Fear factors into nearly everything we do in life. And overcoming it can be euphoric. So why is fear such a beloved part of surfing? The author delves in.

General McChrystal is retired from the Army and the author of the forthcoming “On Character: Choices That Define a Life.” Fear defines us. Not by its presence, but by how we respond to it.

It is wise for investors “to be fearful when others are greedy and to be greedy only when others are fearful,” according to one of Warren Buffett’s classic aphorisms. That’s partly why, a ...