

From Wikipedia:
Human life expectancy is a statistical measure of the estimate of the average remaining years of life at a given age.
What you described would be the median, not average. Those can be very far apart, a good example is the distribution of wealth. Put 10 homeless people in a room with Bill Gates and everyone’s a billionaire on average.
Sorry for being nitpicky and thanks for naming them all. I just assume the term average is equivalent to mean average in peoples heads. For uneven distributions, like wealth or life expectancy are I assume, mean average in itself just wouldn’t be a useful measurement.