The brain likes to save its energy by connecting actions to specific behaviors - the habits. These can range from the "how you wash your hands" routine, your reaction to unexpected meetings, the dynamics of your relationships, or how you organize your workday. These habits are a quick and easy way to take the necessary actions on a daily basis, but by focusing only on your habits you are making your brain fall asleep, leaving it only to do actions it already knowns without evolution.
Change is a difficult action for the brain. Just think how hard it is to stop drinking that daily coffee or start your day an hour early! It's difficult to interrupt such ingrained patterns of behavior. Change threatens the stability of habits and self-control and introduces the possibility of having to face failure/pain when changing to a new way of doing, thinking and being.
Only when change is fully accepted and there is a good chance of victory, benefit and success, does the brain accept change. So, for change to be truly implemented, it must be a conscious choice - your decision - in order to avoid being seen by your brain as a threat, but as a reward. Learning how to overcome negative thinking patterns will help you deal with adversity and perform better.