cont.

... people who refuse to inoculate their children, because they don't know anyone who ever got polio or rubella (i.e., anti-vaxxers).  But the dangers are real, and they are out there.

Another factor influencing my outlook comes from archaeology.  See for example https://scahome.org/publications/proceedings/Proceedings.07Fong.pdf , for the kind of lives people led, living 'close to Nature', without any synthetic chemicals in their diet or environment.  This paper describes Native Americans from the eastern Bay Area of CA from around 1000 A.D.  I have visited another archaeological dig on the San Francisco Peninsula with burials of about the same age.  In the latter case, the archies found age-at-death profiles with two prominent spikes - individuals less than ~5 years old, and individuals slightly over 40.  In other words, you had about 50:50 odds of making it out of early childhood, and if you did, you possibly lived until the ripe old age of 45.  :-/  This, in one of the ...