There are two things I remind myself constantly of and they're Purpose and Persistence.
If I am not doing something with purpose, then why am I doing it? I remember when I made a mistake as a child I would say "I didn't do it on purpose!" Instead of: "it was an accident!" It never hit me so hard until I was a bit older and realized that there should be intention behind what you do - otherwise hapless accidents take place.
And persistence ahh, the bane of my existence. It requires patience and utter dedication. There's no getting bored with persistence and there's no giving up, you must prevail by continuing. To always strive for what your goal is an amazing thing, even when it's rough and seemingly impossible. If you give up because of difficulty then what reason is there for any sort of effort?
Give your all continuously. It's not something you can do one time and call it quits. Find your way into the fog and when it's cold and confusing and you have no damn clue how to get out - keep going.