All habits serve you in some ways. “It’s the solution to a recurring problem that you face throughout life, one that you’ve employed so many times that you can do it without thinking. If the solution doesn’t work anymore, then your brain will update it.” — 4 components of a habit : cue, craving, response, reward. When you enter a room, the cue is walking into the room and finding it dark. The craving is feeling that there would be some value in the room not being dark. The response is flipping on the light switch, and the reward is that the room is no longer dark