One thing to keep in mind is the sense of urgency that the WTS has always shown when it communicates with the rank and file. Even when they talk about not knowing, they still imply that the end is very close. No JW ever thought that armageddon would start 20, 30, or more years down the road. It's always right around the corner and it doesn't make sense to have any future plans for your secular life, when the end is so close.
I remember thinking that I would not have to worry about what I would do after high school, since the end would certainly come before then. I graduated in 1986.
When you have been expecting the end for a long enough time, you stop anticipating it. You're too scared to break away and plan for the future, but you have given up hope that the end will arrive soon. If anyone had told me in 1986 that I would still be in "this system of things" forty years later, I might have left much sooner. The correct question isn't 'how many JWs think the end is near?' The correct question is 'how many JWs live their lives as if the end is near?' The answer? Very, very few.