I'm not sure I can say how or why, unless you agree to the principle that emotions are in synch with planetary movements which isn't that far fetched. I'm not sure I even care. What I do care about is the fact that there is/was sufficient evidence for me to warrant investigating its effect which at times was simply astonishing.
I'll give you an example..
I was trading the FTSE, and based on a value that is perceived to be its inception date (which is obviously open to debate) and using certain planetary aspects I was able to get a "forecast" for potential highs and lows in the future. So with my hourly chart, I knew that a few days later there was going to be a turning point at precisely that hour.
I sent this to a friend, and said watch FTSE at this time etc.
I kid you not..right on that hour I bought the FTSE. And I then sold the FTSE at the next turning point. I of course didnt get the high and low, but I got the exact time.
I thought I was onto the holy grail..its the closest I've ever got. It was just erratic as it was unclear exactly which planets etc might be influencing and sometimes the hourly wasn't the best but the 2 hourly etc etc. So there were times that it wasnt in fact the low, but an intermediate low, or even the high!
Long story short..I had over a dozen times it was spot on, and also other times that it wasn't. That for me wasn't enough and so I have a much simpler system now that I can predict much better with nothing to do with planets. But there is no doubt in my mind, there is something there in those planets for any "non believers"
what I didn't do was actually try to refine using other methods. Doesn't mean I wouldnt ever go back though.