I love the idea of building one's "reservoir of willpower." The idea that this reservoir is built by making good choices over time sound very Aristotelian!
"The facts, it is true, are called by the names of these habits when they are such as the just or perfectly self-mastering man would do; but he is not in possession of the virtues who merely does these facts, but he who also so does them as the just and self-mastering do them." (Nichomachean Ethics)
Thank you for your post!