Was this ever explained?

In the restaurant scene, Bill tells his wife if she remembered how he told her his parents died. He had a nightmare since he was ten, of where his house was burning and he told his parents it was, but they did not believe him. I might not have watched the entire film, but was it ever explained why they did not? You would probably think they would have believed him. I know this is just a film, but can anyone please explain this to me? I also think could not make out what he told his wife the day after it happened, he was at school and something. Please help, thanks.