Pre 1995 - the "generation" refers to individuals who were alive in 1914. The generation of 1914 would not pass away before the end of the system of things. This meant you would expect the end within 100 years of 1914, give or take.
Post 1995 - the "generation " refers to individuals around at the time of christ's presence. These individuals being independant of 1914 or any other date. The end of the system of things is therefore no longer dependant on 1914.
The most amazing thing to me is that Witnesses don't even seem to have the mental steam to define their terms and paraphrase the statement to see if the post 1995 definitions will evaluate to anything intelligible.
For example, Pre 1995:
This Generation = Individuals alive in 1914
Pass Away = Die of old age
All these things = The entire sign including Armageddon
Put it all together and you get something like this:
"Those alive in 1914 will not all die of old age until the entire sign is fulfilled and Armageddon occurs."
However Post 1995:
This Generation = People contemporary with the sign who take no note
Pass Away = Destruction by God at Armageddon
All these things = The entire sign including Armageddon
Put this all together and you get something like this:
"Those contemporary with the sign who take no note will not be detroyed by God at Armageddon until the entire sign is fulfilled and Armageddon occurs."
--which is an obvious tautology. Of course no one will be destroyed at Armageddon until Armageddon occurs. The JW's have reduced the statement to a semantic nil while at the same time, patting themselves on the back for their "Clearer understanding."
Try it get a JW to perform this simple exercise and see just how "Clear" their understanding is.