When asked if he was trying to achieve immortality through his work, Woody Allen said he was trying instead to achieve immortality through not dying.
A number of posters have commented on not giving in to old age. I am in that camp. Walter said that most dive fatalities are the result of diver error. I don't know the exact breakdown, but I believe the largest individual category would be health issues related to aging. The only dive fatalities with which I have had any personal connection were brought on by heart attacks. As we age, various infirmities creep into our system, making it more prone to failure. I am of an age where those issues will grow.
And so, I will some day have to make a decision. At some point my health may reach a point where the likelihood that I may have a problem which may put others at needless risk will grow to the point that I will have to give up the sport. Until then, I will continue to dive, for the same reasons expressed by others who don't want to wither away throughout old age.
For those who feel that way, I leave you with a few quotations that may help you:
Do not go gentle into that good night,
Old age should burn and rave at close of day;
Rage, rage against the dying of the light.
---Dylan Thomas
Come, my friends,
'Tis not too late to seek a newer world.
Push off, and sitting well in order smite
The sounding furrows; for my purpose holds
To sail beyond the sunset, and the baths
Of all the western stars, until I die.
It may be that the gulfs will wash us down:
It may be we shall touch the Happy Isles,
And see the great Achilles, whom we knew
Tho' much is taken, much abides; and though
We are not now that strength which in old days
Moved earth and heaven; that which we are, we are;
One equal temper of heroic hearts,
Made weak by time and fate, but strong in will
To strive, to seek, to find, and not to yield.
---Alfred Lord Tennyson
But at my back I always hear
Time's winged chariot hurrying near;
And yonder all before us lie
Deserts of vast eternity.
...
Thus, though we cannot make our sun
Stand still, yet we will make him run.
---Andrew Marvell