What's the story of Uncle Kai forgetting to bring his umbrella when he went out?

The story of this book is that he forgot to take an umbrella when he went out. It's about a man who goes out and it rains after a while, but he doesn't have an umbrella. For example, it rains outside, just like some unexpected things will happen in our daily life. We should be prepared for the unexpected things that will happen. So this story is a very enlightening story, which can tell people some truth. Get everything ready.