Full disclosure: If you buy the book through the link, it won't cost you any more, but I'll get a few pennies. But my main motivation for doing this is to understand the book properly. What follows is my summary of the chapter.
The author, Jeremy Dean had a power cut. He looked out of the window and saw that the neighbours' lights were off too, so he called the power company and they said that the engineers were on their way. He lit candles, and went to the bathroom. He flicked the switch, and nothing happened. It took a fraction of a second to understand why. Two hours later, the lights were still off when he went to the bathroom again, and flicked the switch again. Still no light.
Derp! What was he thinking?
Absolutely nothing. A habit is what happens when you're not thinking. You might like to look up Skinner's pigeons (Http://psychclassics.yorku.ca/Skinner/Pigeon/)
Humans aren't pigeons. For one thing, they have dreams and goals. In theory, our goals decide out actions – dream of a clean house, get out the mop and bucket. But all too often our dream of getting slim doesn´t stop slices of black forest gateau falling into our mouths. It's partly that strong habits pop back up as soon as you stop concentrating, but there's more going on.
Your environment cues habits. Mostly this is a good thing, because it frees up your brain for other stuff. But it's out of conscious control. Give people sneaky reminders of old age and they'll walk more slowly afterwards. Stereotypes can be nastier than you think. Or they can be helpful – remind Asian-Americans of Asian stereotypes before a maths test, and they'll get much higher scores (because they answer more questions). Remind people of intelligence before a general knowledge test and they'll do better at that too.
Which might explain why it's easier to change habits when you've just moved. Your old environment isn't there to cue your old habits.
Direct cuing is when something in the environment elicits your behaviour. In the common room with Pat and Chris = switch the TV on.
Motivated cuing is when the habit becomes completely divorced from the original goal. For example, when you're a student, you go out drinking with friends. You learn to associate alcohol with freedom and good company. Years later, socializing is still associated with alcohol. Give people sneaky reminders of socializing, and they're more likely to pick the “Free beer” voucher than the “Free coffee” voucher. And once you take a drink you're thinking less clearly and running more on habit, so you're more likely to take another and another. It can get out of hand.
This sort of disconnect is common. Once you associate “Go somewhere else” with “Car”, it becomes very hard to walk to the shops. You want a carton of juice and you're behind the steering wheel and halfway there before you remember - “Oh yeah, I was going to start walking.”
It's all too easy for humans to wind up doing things which don't align with their long-term goals. There's far too much going on in the unconscious.