i use the 20 year generational divides to understand a lot of things, but I didn't know it had an actual planetary background. 

lots of  babies are born on the full moon. so i know the moon cycles do have some very obvious effects on humans.

the astrology stuff is a little less predictable but i have noticed personally that I tend to date  anyone born in late August/early September timeframe, and close friendships with people in late February/early march.  I don't know if I just imagine similarities between characters and birthdays to help me understand people and I ignore all the exceptions, or if there really are similarities.

fun to think about.