Of course, according to Genesis life spans were much longer prior to the flood so although Noah could have preached for hundreds of years to the same people yet it was only recorded as about 40 years.
Unlike 1876 until now which would have meant my great great grandfather hearing it in 1876 at approx age 24, then my great grandfather hearing it at age 24 in 1900 then my grandfather hearing it at age 34 in 1924 then my father in 1950 then me in 1976 and then my children in 2000 - so six overlapping generations of which only the last two are alive.
Crazy!