I think Martha Graham explains it best in her quote below:
“There is a vitality, a life force, a quickening that is translated through you into action, and there is only one of you in all time, this expression is unique, and if you block it, it will never exist through any other medium; and be lost. The world will not have it. It is not your business to determine how good it is, not how it compares with other expression. It is your business to keep it yours clearly and directly, to keep the channel open. You do not even have to believe in yourself or your work. You have to keep open and aware directly to the urges that motivate you. Keep the channel open. No artist is pleased. There is no satisfaction whatever at any time. There is on a queer, divine dissatisfaction, a blessed unrest that keeps us marching and makes us more alive than the others.”
And when I feel the unrest, "I just Gotta".