To succeed, you must have tremendous perseverance, tremendous will. “I will drink the ocean”, says the persevering soul; “at my will mountains will crumble up”. Have that sort of energy, that sort of will; work hard, and you will reach the goal.
Swami Vivekananda, Vedânta philosophy: Lectures by the Swâmi Vivekânanda on Râja Yoga (1899), Ch. VI