As long as the sky is long, so long is the earth. Forgive me for being stupid. I thought about it for a long time and couldn't find a suitable answer, but I got the idea to write a novel about eternity.
As for why I turned from philosophical thinking to writing novels, there is actually nothing I can do about it. When I write articles, I always tend to go off topic. Writing about the death of a loved one triggers feelings about life, and the end of the article often ends with the relative pretending to be dead. So you can't expect me to think clearly about the way back to the bridge.
All in all, this is a warm and affectionate novel. And it's probably true.