If you want to lift a hundred pounds, you don't expect to succeed the first time. You start with a lighter weight and work up little by little. You actually fail to life a hundred pounds, every day, until the day you succeed. But it is in the days when you are exerting yourself that the growth is occurring.
The Brain That Changes Itself: Stories of Personal Triumph from the Frontiers of Brain Science (ed. Penguin, 2007) - ISBN: 9781101147115