What's your definition of "old?"
You are already close to death's door...
That varies greatly from person to person. I ran an outdoor adventure group for the first three years into my retirement. My oldest hiker, who made it up the 13-mile, 7,000+ vertical from 6,500 to 14,15 feet top of Pikes Peak, was 78. Hardly "close to death's door," wouldn't you say?
The ancient Egyptians median life was 40 .. anything over that is just gravy IMO.
All "median age" figures include infant mortality, which greatly skews the results. The correct approach is to find the median age. That age more accurately reflects how old people can expect to life if they survive childhood. That age has actually been nearly constant throughout the last 2,000 years, as this article
clearly explains. It even uses your Egyptian example as evidence of the myth:
An article on Egyptian pyramid builders in the November 2001 issue of "National Geographic" noted, "Despite the availability of medical care the workers' lives were short. On average a man lived 40 to 45 years, a woman 30 to 35."
Again, the high infant mortality rate skews the "life expectancy" dramatically downward. If a couple has two children and one of them dies in childbirth while the other lives to be 90, stating that on average the couple's children lived to be 45 is statistically accurate but meaningless.
And finally, it reveals the average age we've enjoyed for the last 2,000 years:
When Socrates died at the age of 70 around 399 B.C., he did not die of old age but instead by execution. It is ironic that ancient Greeks lived into their 70s and older, while more than 2,000 years later modern Americans aren't living much longer.
When using statistics, it is supremely important to know the difference between terms like "mean" and "median," as well as how one is appropriate to use in some circumstances, but not others, and vice-versa. Without such knowledge, comments like, "The ancient Egyptians median life was 40" are worse than meaningless. They're very misleading.
Here's an outstanding graph
which shows life expectancy based on having reached certain milestone ages (birth, 5, 20, 40, and 60). As you can clearly see, once you reach age 60, there's been very little change in the ultimate age since 1850, rising only a few years from about 73 to about 79. Furthermore, as the note says, "The greatest change in the overall life expectancy of American man since 1850 resulted from an increasing liklihood that they would reach the age of 5."
Never use the arithmetic mean when median is a more appropriate measure of central tendency.
Finally, here's a good article
contrasting the difference between Lifespan (independent of whatever age you might be) and Life Expectancy (dependent on your age).