But countless studies have shown that a cue and a reward, on their own, aren't enough for a new habit to last. Only when your brain starts expecting the reward--craving the endorphins or sense of accomplishment--will it become automatic to lace up your jogging shoes each morning. The cue, in addition to triggering a routine, must also trigger a craving for the reward to come.

Rather, to change a habit, you must keep the old cue, and deliver the old reward, but insert a new routine.

Cravings are what drive habits. And figuring out how to spark a craving makes creating a new habit easier.

This is the real power of habit: the insight that your habits are what you choose them to be.

Hiding what you know is sometimes as important as knowing it.

If you believe you can change - if you make it a habit - the change becomes real.

The biggest moment of flexibility in our shopping habits is when we have a child, because when you think about it, all of your old routines sort of go out the window, and suddenly a marketer can come in and sell you new kinds of things.