From Wind, Sand and Stars (1939)  by Antoine de Saint-Exupery

Once again I had found myself in the presence of a truth and had failed to recognize it. Consider what had happened to me: I had thought myself lost, had touched the very bottom of despair; and then, when the spirit of renunciation had filled me, I had known peace. I know now what I was not conscious of at the time-that in such an hour a man feels that he has finally found himself and has become his own friend. An essential inner need has been satisfied, and against that satisfaction, that self-fulfilment, no external power can prevail. Bonnafous, I imagine, he who spent his life racing before the wind, was acquainted with this serenity of spirit. Guillaumet, too, in his snows. Never shall I forget that, lying buried to the chin in sand, strangled slowly to death by thirst, my heart was infinitely warm beneath the desert stars.