Indeed, I was part of the 1975 JW generation. I remember taking a mountain vacation with another Witness family in 1974, and we thought it would be the last time the families would do that before the end. It amazed me a few years later when I brought this up to them how upset they became. They wrote a letter to my JW spouse saying I was trying to "stumble" them. It's unbelievable how some can deny the obvious in cult-like religions.
As many already said, 1975 ended with the sounds of silence from the Tower. When Witnesses awoke on January 1, 1976 nothing changed for "Satan's world" nor for JWs, and outright questions about failed expectations was unthinkable for most Witnesses. However, the Tower's silent treatment started to have an effect.
members received rebukes, not an apology, for putting faith in the Watchtower Society's expectation. As larc pointed out, the Tower did the same thing in 1925 (no, I wasn't there). In response I resigned as an elder in 1977, and by 1978 only attended a few meetings, and soon none at all.
Yes, I remember it well--but of course only apostates have good memories. It seems that part of the brain is removed when one has "the Truth."