Neurologists studying brain disorders have discovered remarkable behaviors. In one case, a woman suffered from severe short-term memory loss. Anything more than five minutes old never happened. Every morning, she woke up with no recollection of anything less than a year or two ago. She knew her name and her distant past, but nothing recent.

Each day, she'd visit her doctor. He would shake her hand, reintroduce himself, and they would start over. One day, in a fairly unethical experiment, he put a thumbtack in his hand. When they shook hands, she was pinched. It hurt. He explained to her what he had done, and of course, an hour later she had forgotten all about it.

The next day, though, when the doctor extended his hand, she flinched. How did she know about the thumbtack? Her short-term memory was clearly gone. She wasn't faking. And yet, she remembered enough to avoid the pain. This was her another part of the brain at work. It has its own memory, its own survival system in place which jumping into action whenever basic survival needs are at stake. And when it is aroused, the other part of our brain stands little chance.

Linchpin: Are You Indispensable?, Seth Godin