If

"If you can keep your head when all about you
Are losing theirs and blaming it on you;
If you can trust yourself when all men doubt you,
But make allowance for their doubting too
If you can make one heap of all your winnings
And risk it on one turn of pitch-and-toss,
And lose, and start again at your beginnings,
And never breathe a word about your loss
Yours is the Earth and everything that's in it,
And---which is more---you'll be a Man, my son!"

Courtesy : Rudyad Kipling (If)