Many of the things that help you grow are very simple, but require lots of effort. Building habits, working out, speaking up, eating healthy, actually doing work. These are all things that require an investment of energy, time, and many other valuable resources.
Your reptile brain detests investing. It will only spend just enough to get by, to survive. In caveman era, it would've been too risky to spend your resources. Back then resources were scare.
But we're not in Caveman Era anymore.
To succeed at anything you must be willing to invest your resources. In today's society resources are endless, you just have to look for them. You have to invest without expecting immediate returns. To do this you have to keep your mind focused on your desired goals and outcomes. You have to overcome your fears, get out of your comfort zone. Become comfortable being uncomfortable.
Have clear goals, and a clear plan that will get you from where you are right now to where you want to be.
Maneesh Sethi from hackthesystem.com has created a guide/worksheet that will help you actually achieve your goals. It will help you hack your habits to become more productive and successful. It helped me finish this very post. Click here to get his guide to hacking your goals.