This was the main stumbling point for me when the understanding of the term "Generation" was altered in 1995. I resented the implication greatly, and even though I was an elder at the time, it was a turning point and the impetus for my eventual exit.
The notorious quote:
"Eager to see the end of this evil system, Jehovah's people have at times speculated about the time when the "great tribulation" would break out, even tying this to calculations of what is the lifetime of a generation since 1914"