Energy conservation, storage and expenditure are all items that…
Energy conservation, storage and expenditure are all items that are important enough for you to make them into a habit. Therefore you should try to habitually gather positive energy, conserve positive energy, and avoid negative energy.
— from Fuel (Energy)
In the book
From there, guard the fuel: refuse to spend it on the non-productive, learn to say no, and keep not only a to-do list but a "to-don't" list of what you will no longer indulge. Make the good habits easy and the draining ones inconvenient so the structure spares your willpower, and settle conservation, storage, and wise expenditure into habits rather than daily decisions. To my children, and to theirs: — Fuel (Energy)