" Because of reasons they were just beginning to understand, that one small shift in Lisa's perception that day in Cairo -the conviction that she had to give up smoking to accomplish her goal- had touched off a series of changes that would ultimately radiate out to every part of her life.
When researchers began examining images of Lisa's brain, they saw something remarkable: One set of neurological patterns -her old habits- have been overridden by new patterns. They could still see the neural activity of her old behaviors, but those impulses were crowded out by new urges. As Lisa's habits changed, so had her brain. "

― Charles Duhigg , The Power of Habit: Why We Do What We Do in Life and Business