One of my relatives vehemently denies that the watchtower society said anything about 1975.
My mother insists that she understood this to be the case from very early on, and once told me that she corrected the woman giving her the Bible study when she was just starting. I am sure she believes that this is what happened now, but I don't believe it for a moment. I think she joined because she thought it was going to happen and figured that Armageddon would be a quick ticket out of a dreary life she had trapped herself in.
When 1975 came and went and nothing happened, she accepted the company line and kept waiting for the end, since it was "very close." Almost 50 years later, she's still convinced that it will come any day now. She's a very smart and capable person, who squandered her talent and ability because she was waiting for something better to come along.