When we start making changes in our life we sometimes don't notice them or the benefits of those changes because they have become our new norm.
Looking back and evaluating how far you have come is absolutely key to moving forward because, how you do one thing is how you do everything. So if you have changed one area of your life you can certainly apply what you have learnt to other areas that you want to change.
Looking back inspires you to look forward!
Jonny