I was around (baptized in 1961) when the 1975 thing was going on. Many witnesses will tell you that the Society never said that Armageddon would come in 1975 but EVERYONE believed it. That’s all the friends could talk about at that time, including the CO’s and DO’s. Where would we have gotten that idea from? Look up the w68 5/1 page 271 and read that article. Note particularly paragraph 5 : “Therefore, God’s seventh day and the time man has been on earth apparently run parallel. To calculate where man is in the stream of time relative to God’s seventh day of 7,000 years, we need to determine how long a time has elapsed from the year of Adam and Eve’s creation in 4026 B.C.E. From the autumn of that year to the autumn of 1 B.C.E., there would be 4,025 years. From the autumn of 1 B.C.E. to the autumn of 1 C.E. is one year (there was no zero year). From the autumn of 1 C.E. to the autumn of 1967 is a total of 1,966 years. Adding 4,025 and 1 and 1,966, we get 5,992 years from the autumn of 4026 B.C.E. to the autumn of 1967. Thus, eight years remain to account for a full 6,000 years of the seventh day. Eight years from the autumn of 1967 would bring us to the autumn of 1975, fully 6,000 years into God’s seventh day, his rest day.”
Paragraph 6: “…Hence, when Christians note from God’s timetable the approaching end of 6,000 years of human history, it fills them with anticipation. Particularly is this true because the great sign of the “last days” has been in the course of fulfillment since the beginning of the “time of the end” in 1914. And, as Jesus said, “this generation will by no means pass away until all these things occur.” (Matt. 24:34) Some of the generation that discerned the beginning of the time of the end in 1914 will still be alive on earth to witness the end of this present wicked system of things at the battle of Armageddon.—Rev. 16:14, 16.”
Read the article “How Are You Using Your Life” (km 5/74) and note what it says toward the end in particular: “Yes, since the summer of 1973 there have been new peaks in pioneers every month. Now there are 20,394 regular and special pioneers in the United States, an all-time peak. That is 5,190 more than there were in February 1973! A 34-percent increase! Does that not warm our hearts? Reports are heard of brothers selling their homes and property and planning to finish out the rest of their days in this old system in the pioneer service. Certainly this is a fine way to spend the short time remaining before the wicked world’s end.—1 John 2:17.”
So if you want to be honest in your reply to the man who questioned you in service tell him that it was indeed an error. W80 3/15 “Choosing The Best Way Of Life”, five years after the 1975 fiasco finally gave a half-hearted apology for the error: “In modern times such eagerness, commendable in itself, has led to attempts at setting dates for the desired liberation from the suffering and troubles that are the lot of persons throughout the earth. With the appearance of the book Life Everlasting -- in Freedom of the Sons of God, and its comments as to how appropriate it would be for the millennial reign of Christ to parallel the seventh millennium of man's existence, considerable expectation was aroused regarding the year 1975. There were statements made then, and thereafter, stressing that this was only a possibility. Unfortunately, however, along with such cautionary information, there were other statements published that implied that such realization of hopes by that year was more of a probability than a mere possibility. It is to be regretted that these latter statements apparently overshadowed the cautionary ones and contributed to a buildup of the expectation already initiated.”
The younger ones today have no way of knowing just how ingrained this was in us and the older ones (well, most of them) have been convinced that it was their error in the first place. There is plenty more information if you would like to see it. Research it on your CD library.