"...I remember the generation change...it went from being of understanding age in 1914 from being born in 1914..."
There was a another, smaller change in there too. At one time the 'age of understanding' was said to be "about 15 years old." That was later changed to being 10 years old, which bought Watchtower a few more years.
In those days Watchtower said you had to be old enough to understand that Bible prophecy about the last days was being fulfilled, at least have a very basic understanding of it, to be of the generation.
Then the age of understanding was dropped completely and it was being born in 1914 that counted. Of course that failed too.