Obstacles are necessary for success because in selling, as in all careers of importance, victory comes only after many struggles and countless defeats. Yet each struggle, each defeat, sharpens your skills and strengths, your courage and your endurance, your ability and your confidence and thus each obstacle is a comrade-in-arms forcing you to become better... or quit. Each rebuff is an opportunity to move forward; turn away from them, avoid them, and you throw away your future.
Og Mandino (2011). “The Greatest Salesman in the World”, p.25, Bantam