It is more like 60% or so, but yes it is that high a proportion of people that will be infected and for most it is no issue at all.
You may already be infected from your youth and not know it.
Yes but that is for all age groups. I was wondering if there were data for people in the age group older than 50? Have you run it this quote I have put a link to?
There often isn't data for older age groups with the studies accepting only up to age 55 or 60.
It varies a lot by country and is generationally changing such that today's 30 year olds will have a lower incidence at age 65 than the current cohort.
I think its a safe assumption that over half the population alive today will become infected before they die, excluding a vaccine being released.