Note, this isn't generally true. The low average life expectancy in those ages is skewed down by infant mortality and conflict. In a way, human life span follows a bathtub curve so reducing infant mortality in our (modern) age has massively increased the average life expectancy, but it doesn't mean people in those days didn't live past 40.
Or, exaggerating mildly: nobody lived for 30 years back then; half the population didn't make it past their first birthday, the other half lived for 60 years.
Yes. I agree with the lifespan information you've laid out.
There has been a misconception amongst laymen that our lifespans have become longer for a number of reasons because it is usually framed in a way that bolsters the notion that all those who came before had shorter lifespans than we are likely to enjoy.
That isn't really the case because obviously if someone mentions an average lifespan or a median lifespan then that is the number that sticks in the memory and most people whiff on the fact that with any average or median, around 50% of the people lived longer and 50% of the people did not live as long. No upper bound is given and the lower bound is intuitively occupied by those who didn't survive infancy.
In hindsight, I should've framed that differently. I was attempting to illustrate that it doesn't take much time at all to cover a lot of ground and if you are motivated by the need to feed yourself or your family or if you just feel the unshakable need to see what is over that distant hill then a short lifespan still offers plenty of opportunity to see the world and scratch those itches.
I spent several months when I was younger living on the road and in the back-country. I knew every morning that my primary goal needed to be locating drinkable water for myself, my traveling partner, and our horses and my secondary goal was finding food. We carried our shelters and implements that we would need to keep all our gear in order but water and food were paramount concerns. We were young and totally not clued in to all the planning that would normally be involved in undertaking a multi-week, multi-state trip so inaccurate assumptions were made about accessibility, cost, and availability of necessities. We had fun, we survived our own incompetence and we moved on with new skill-sets and an enhanced appreciation for how the real world really works.
Note, this isn't generally true. The low average life expectancy in those ages is skewed down by infant mortality and conflict. In a way, human life span follows a bathtub curve so reducing infant mortality in our (modern) age has massively increased the average life expectancy, but it doesn't mean people in those days didn't live past 40.
Or, exaggerating mildly: nobody lived for 30 years back then; half the population didn't make it past their first birthday, the other half lived for 60 years.