If Jesus created the universe and the planet like JW believe he would have certainly known that two homo sapiens called "Adam and Eve" was likely a story. Even if he perhaps knew this was the case, he could probably not tell the truth about the real age of human race but only speak in parables, because they would have thought he was a charlatan or spoke halftruths or even that he was a blatant liar. He would have not destroyed the Jewish religion and brought more science to the world, but would have been stoned earlier.
So, TheWonderofYou, Jesus had to lie so that the people of his time wouldn't think that he was a liar.