I was a teenager in 75, but i remember the late 60s to 75 - all the speculation of Armageddon. I remember that it wasn't written in stone, there was some wriggle room, as far as it might not happen in 75, but it was harped on so much that it 'might' happen that the first half of the 70s decade was nothing but anxiousness for the average JW.
My parents stayed faithful post-75, dragging us kids along (I wasn't rebellious enough to question theirs or the WT's authority - as I should have done) for the ride. They really weren't affected by the failure.
My mother is still as faithful and zealous as she was in 74. Doesn't blink an eye at changes in doctrine or failed predictions. She defends the WTS to the hilt. She'll die a faithful JW, and I don't even discuss it with her anymore. If it makes her happy in her last few years, then who am I to rob of her happiness...