To start anything you need a reason why.
Why are you on a diet?
Why do you workout?
Why do you goto work?
Why do you practice music?
Why do you blog?
Why are you in a relationship with that person
There is a reason why you are doing the things you are doing. Chances are that some time has passed and you are not the same person that you were when you started this journey to begin with. So is you why still relevant or valid? If it is not then why are you still doing it? If it is valid then it is even more motivation to work harder for what you want.