This is exactly why Jesus told His disciples, “No man knows the day and hour but the Father, not even I.” There have been many times throughout history man thought it was over, only to have things bounce back. Yes, there are signs we can watch for. For instance, everyone thought Pope John Paul II was the Antichrist after he was shot(grievous wound that was healed). It turned out to be farther from the truth. Y2K, people were dumping everything because they thought that was it. Recently, you had the Harold Camping fiasco. Now, you have the unrest in the MidEast, and people beginning to pipe up.
I do not go about my daily toil worrying about “the last day”. I have accepted my mortality.
Never challenge a man who has nothing left to lose.