Boris Johnson, who spent days in intensive care fighting Covid, did not want to lock down the UK to limit its spread because most of those dying were more than 80 years old.
The message read: "I must say I have been slightly rocked by some of the data on COVID fatalities. The median age is 82 – 81 for men 85 for women. That is above life expectancy. So get COVID and live longer."
"Hardly anyone under 60 goes into hospital (4 per cent) and of those virtually all survive. And I no longer buy all this NHS overwhelmed stuff. Folks I think we may need to recalibrate."
A second message said: "There are max 3m in this country aged over 80. It shows we don't go for nation wide lockdown."
I couldn't quickly find UK figures, but according to the CDC, 43% of deaths involving Covid were of people under 75 years of age. The number of victims under 80 years of age would be higher—more than 50%.
The misinterpretation of "median age" as "most people" is the specific failure at hand. It's a good example of what happens when everyone in the room is superficially well-educated but specifically innumerate, as is the case with gatherings of people around the person of Boris Johnson. So they wander into a pseudoscientific fantasy land where the only people under the age of 80 at significant risk have only themselves to blame.