It was that Lisa had focused on changing just one habit—smoking—at first. Everyone in the study had gone through a similar process. By focusing on one pattern—what is known as a “keystone habit”—Lisa had taught herself how to reprogram the other routines in her life, as well.
habits as they are technically defined: the choices that all of us deliberately make at some point, and then stop thinking about but continue doing, often every day.
Habits, scientists say, emerge because the brain is constantly looking for ways to save
effort.