I agree that many JWs simply know how to regurgitate what is taught in the halls and not much more.
However, i would like to comment on the post about Noah above. First it is really disturbing that the Watchtower society continues to modify bible verses to scratch itself on the back.
With that said, i must disagree when you say that Matthew 24:39 says that people had no idea that the great floor was coming. In reality by focusing on the words "and they did not understand until the flood came" you are making the same mistake that JWs make, by isolating words in the bible to support a belief.
In order to understand the meaning of what is said here, it's better to simply look at the situation. Jesus was comparing his second coming with the events of the great flood. He indicated they were similar in the sense that people would be caught off guard by his second coming. THIS DOES NOT MEAN that they didn't know that there will be a second coming. Obviously the entire world (hopefully) knows this, yet many will be caught off guard and will only realize what is happening when it's too late.
Same thing in Noah's time. It seems logical to think that those people were also warned, but simply ignored it. The bible in fact does not specifically say that Noah preached about this, but the bible does call him "preacher of rightneouness". Additionally just by applying a little logic to this, it is true that God has always warned people of impending destruction or judgement and most often than not, has always used humans to distribute the warning, so common send tells us that if God is consistent, he would have done the same here.