The Upanishads, sacred Hindu texts, liken taming the mind to taming a wild horse. Little by little, one needs to learn when to slacken the reins and when to draw them in.
"A ship in harbour is safe, but that is not what ships are built for." - John Shedd
"To the person who does not know where he wants to go, there is no favourible wind." - Seneca
When you come to the edge of all the light you have and must take a step into the darkness of the unknown, believe that one of two things will happen. Either there will be something solid for you to stand on or you will be taught how to fly." - Patrick Overton