I think it's quite great to set yourself a big challenge, and then you've got another reason for keeping fit.
Take into account that great love and great achievements involve great risk.
We never know how high we are till we are called to rise. Then if we are true to form our statures touch the skies.

Collected Poems
A man sits as many risks as he runs
Work and struggle and never accept an evil that you can change
It is only in adventure that some people succeed in knowing themselves - in finding themselves
Our greatest foes, and whom we must chiefly combat, are within
I am prepared to die, but there is no cause for which I am prepared to kill
A horse never runs so fast as when he has other horses to catch up and outpace
We shall march prospering, not thro' his presence;
Songs may inspirit us, not from his lyre;
Deeds will be done, while he boasts his quiescence,
Still bidding crouch whom the rest bade aspire.


On Anger: "For every minute you remain angry, you give up sixty seconds of peace of mind."
On Destiny: "Our destiny exercises its influence over us even when, as yet, we have not learned its nature: it is our future that lays down the law of our today."
Human, All Too Human
On Friendship: "A crowd is not company; and faces are but a gallery of pictures; and talk but a tinkling cymbal, where there is no love."