When I got "recruited", I was around 14.
I never believed the Earth was only 6,000 years old, but then again, I don't think many witnesses believe that either. After all, the old green Bible used to have dinosaur pictures in it. They wouldn't put a picture of something they don't believe in, in one of their Bibles. So if they believe dinosaurs existed, they can't believe that the world was around for only 6,000 years.
I've always had my doubts about the 144,000. The explanation they gave me about how they were resurrected and how there were still some on Earth today.
1914 - I accepted and never really did much research on it.
Harmagheddon - Yes I believed it. At first I really believed it, but it slowly faded and after a while I didn't really think about it anymore. I think it's like that for some while others revel in the hope of it coming ASAP.