When he went to bed, he thought about how sleep was similar to death. When he woke up in the morning, he thought about how pointless it was to get out of bed ;after all, everything he had done was just a plaything in the face of what had to come. He might as well lie there and wait to die.
It's realistic, even if the quote appears in a story depicting a fantasy character.
Your article really has a deep sense of "telling the old story", the thoughts of the characters in the story reflect realistic philosophies.