I always though this song was so depressing but now I wonder if they mean that if people knew when they were going to die maybe they would live the way truly makes them happy. Stop caring about what people think, take your dog for a walk, tell the people you love that you love them etc.
my older brother was listening to this song a few months before he drowned, im sure he was happy when he passed, now im listening, sure, i will be happy.