It's one thing to know that you're supposed to develop new habits. It's another thing entirely to teach your subconscious mind to follow that up even when you're relaxing and your mind is elsewhere. The subconscious mind is a rather slow learner and doesn't adapt unless you're very persistent with it for a very long time. Also, it doesn't really care unless it gets a reward. It's not very different from training an animal, except the animal is you.