First of all, we can think like this. We humans may not have evolved from apes at first, but aliens put them in. For example, the pyramids in Egypt thousands of years ago are a good illustration. From the perspective of scientific human development, we can't explain the degree of civilization of architecture at that time, but in fact, we all discovered the secret of pyramid architecture after successfully finding Egyptian manuscripts in recent years. However, there are still many problems to be solved. It can be said that even now, we can't build the pyramids. This view should not be, so it may really be built by aliens.
Perhaps, we humans are really just an object of alien research, and the earth is the environment for our development, and our memory about this is completely blocked. Although it sounds unrealistic, the universe is so big that there are too many things we don't know, so this idea may also have certain possibilities.
We don't know if there is life underground, or if there really is. We live in the most suitable environment on earth, but there are also many places we don't know, such as 10 thousand meters below the ocean, or there are really some creatures that exist in legends and myths. It can only be said that we humans know too little, and these are all possible.