If you were 65 in 1940 (in other words, born in 1875), your life expectancy was 77.7 for men and 79.7 for women.
If you are 65 today (born in 1946), your life expectancy is 83.1 for men and 85.1 for women.
While overall life expectancy is much longer, for adults it hasn’t changed all that much.
What has changed is that a lot more people get to be adults. They don’t die of whooping cough and scarlet fever and pneumonia as so many children once did. Because so many children died young in the past, the average age at death was always much lower then the age at which most adults actually died.
This is an important and widely misunderstood fact.
(The first 10 presidents lived to an average age of 77.5.)