He who always thinks himself as weak will never become strong, but he who knows himself to be a lion, rushes out from the worlds meshes, as a lion from its cage.
If you can force your heart and nerve and sinew to serve your turn long after they are gone, and so hold on when there is nothing in you except the will which says to them: 'Hold on!'
The most important thing in life is to stop saying 'I wish' and start saying 'I will.' Consider nothing impossible, then treat possibilities as probabilities.