Change your life by establishing a keystone habit.
When you want to make a big change, jumping into deep water will probably not work. Instead, start with something small and simple, like journaling.
A very good example from this book is the problem of obesity. Instead of going to the gym and starting a strict diet, start writing down everything you eat each day. That’s it. More habits will build naturally around this one. When you realize what you eat, and how much, you will start to slowly change your habits.