Saw an interesting piece on television as a part of a documentary. A magician and debunker of a great many paranormal claims did an experiment for the camera.
He took a classroom of college students and after collecting in advance their birthdates and places of birth, with exact times if possible) he prepared and passed out at a class meeting, horoscopes to each person and asked them to judge how accurately he had portrayed them.
Whether or not they were believers in astrology, they had to admit that he had described them pretty well and not one person in the class felt that he had totally misread them. Most everyone was at least a little su[rised at the accuracy and the specificity of his readings.
He then asked each person to pass their reading to the person behind them.
You've probably guessed what happened. THe students discovered that they had all received exactly the same reading.
While this does not prove that astrology is a waste of time, energy and intellect, it suggests that there are other explanations to "a good reading" than a knowledge of the stars. I think the principle that is often called Occam's Razor is useful here, where there is more than one explanation but no proof, accept the simple explanation as your working hypotheis. I'll stick with self-delusion as an explanaion. (It's something i know. I am a victim of, too, but in other fields.)