I remember it well. It was in 1974, just befrore the great '75 debacle. I was 15.
A group of then-teenagers were talking about the impending big-A. I was explaining that in my opinion, the 'generation' might not have started until exactly 1914. I said that it seems like supposition that people had to be of 'reasoning age' to see events of 1914. Also, I suggested that this generation wasn't necessarily limited to 80 years; that it could last as long as there is one representative of a generation. Based on that, the Big-A could be as far out as 2014.
You should have seen the reaction. You'ld have thought I was espousing canibalism.
It was then that it was clear that we had to pretend to believe all the bullsh!t. My exit was still a few years out.