I had made up my mind to find that for which I was searching even if it required the remainder of my life.

As quoted in Making a Habit of Success: How to Make a Habit of Succeeding, How to Win With High Self-Esteem (1999) by MacK R. Douglas, p. 45. Unsourced variant: What this power is, I cannot say. All I know is that it exists... and it becomes available only when you are in that state of mind in which you know exactly what you want...and are fully determined not to quit until you get it.