Mary Oliver said this quote

Intellectual work sometimes, spiritual work certainly, artistic work always — these are forces that fall within its grasp, forces that must travel beyond the realm of the hour and the restraint of the habit. Nor can the actual work be well separated from the entire life. Like the knights of the Middle Ages, there is little the creatively inclined person can do but to prepare himself, body and spirit, for the labor to come — for his adventures are all unknown. In truth, the work itself is the adventure. And no artist could go about this work, or would want to, with less than extraordinary energy and concentration. The extraordinary is what art is about.