When you argue for your limitations, you get to keep them. - Gary Keller

direction: the majority of what you want will come from the minority of what you do.

Even if you’re on the right track, you’ll get run over if you just sit there.” — Will Rogers

Knowing why you're doing something provides the inspiration and motivation to give the extra perspiration needed to persevere when things go south..
..Purpose provides the ultimate glue that can help you stick to the path you've set. When what you do matches your purpose, your life just feels in rhythm, and the path you beat with your feet seems to match the sound in your head and heart. Live with purpose and don't be surprised if you actually hum more and even whistle while you work.