This comes down to motivation and subconscious beliefs. Pain and pleasure are what motivates us and the reality is that most of us are not in enough pain to stay properly motivated and most of us can't envision the future pleasure vividly enough to use this as motivation either. In essence, we are comfortable enough where we are. The other reason is that you most likely have subconscious sabotaging behaviours that are deeply imbedded. These are critical to identify and replace. Both these issues are best worked with through a certified life and wellness coach. See our site for more information to access this service.