Happy the man, and happy he alone,
He who can call today his own:
He who, secure within, can say,
Tomorrow do thy worst, for I have lived today.
Be fair or foul or rain or shine
The joys I have possessed, in spite of fate, are mine.
Not Heaven itself upon the past has power,
But what has been, has been, and I have had my hour.
John Dryden
http://www.poemhunter.com/poem/happy-the-man/
