You said "the characteristics attributed to star signs are quite often true." Leaving aside the vagueness of "quite often", if you take a set of specific characteristics it will apply to some people in any group or cross-section. Take a bunch of people supposedly born under the same star sign, and some of them by law of averages will have those characteristics. This emotional/logical thing - for a start I don't believe you spend the WHOLE of your time being emotional while he works ENTIRELY from a position of logic - that would make you a couple of sitcom characters. But regardless of how true that is, the emotional/logical split will be true of many people no matter what their birth date is. It's often true of male/female couples generally and they're frequently seen as recognisable male/female right side/left side qualities.
I don't find it remotely interesting, and in no way "spooky". Let's say you do believe in it. What are you going to do with it? Use it determine who you're with, who your friends are, what path you take in life? And why is it linked to birth date - why not to date of conception, or date of a particular phase of cell division of the embryo, etc? Do the dates change depending where on the planet you were born?