How do fortune-telling books collect relevant information? Is there any basis?

One is cheating, guessing your question according to your answer. This kind of fortune telling is not surprising. Another kind of fortune-telling is that you are talented and can see other people's things clearly, but not all of them. It can be said that you are smart. Another kind of fortune telling is to know gossip and some numerology. It is recorded in Zhouyi according to the principle of five elements. There is a certain scientific basis. But now fortune tellers should belong to the first category.