Excellent post David Jay.
For me 1975 should have woken me up but in my defence I was only a teenager then, being brought up in it. But 1995 (first big generation change) should certainly have woken me up - although looking back that was when I think the doubts started.
I have lived through the only reported reverse of numbers (1977 and 1978 I think) and it didn't make a difference to me.
But I think that seeing another reverse in figures would help me in that I believe this would be the beginning of a decline rather than a blip before a further large increase.
A "ship of fools" as you describe them puts it well.