Why can't you say it the morning after the nightmare?
Actually, it's a superstitious statement, and there are many opinions on this issue. According to scientific theory, dreams are the true reflection of your innermost feelings, and Duke Zhou thinks that every dream represents a sign. If so, nightmares are not necessarily a bad thing. About telling nightmares, some people think that nightmares can't be told, but they will become true. Others think that if you have a nightmare, you must say it, and the more you tell people, the better, so that you can crack it. You know how hairy people are, right? It depends on which one you believe, or which one is more popular in your hometown.