I totally believe in astrology, not horoscopes which I think are just generalization but as far as character traits, I could not POSSIBLY be any more like my sign. I've read extensively about other signs and combinations of signs and it's usually DEAD ON. Why is it assumed to be nonsense because we don't understand it? The moon affects the tides and the crops, why not personalities??
It is not "assumed to be nonsense because we don't understand it." It is proved by investigation to have zero predictive value. You should learn about the
Forer Effect, named after psychologist Bertram Forer, who himself termed it, in a famous paper, "The Fallacy of Personal Evaluation." (The original text of his article, published in 1949, can be found in a PDF file
here or read on line
here.) Forer had the students in one of his classes fill out a questionnaire that he called the "Diagnostic Interest Blank (DIB)." Sometime afterwards, he gave each of them a "personality description" consisting of 13 numbered statements, supposedly derived from the results of the test. The students were then asked to make the following evaluations:
A. Rate on a scale of 0 (poor) to 5 (perfect) how effective the DIB is in revealing personality.
B. Rate on a scale of 0 to 5 the degree to which the personality description reveals basic characteristics of your personality.
C. Then turn the paper again and check each statement as true or false about yourself or use a question mark if you cannot tell.
The average value for the answers to question A was 4.3; the average value in answer to question B was 4.0; and the average number of questions marked "true" in answer to question C was 10.2 (of 13). All but 1 of the 39 students responding rated the DIB a 4 or a 5, and 34 of the 39 rated the personality description a 4 or a 5. In other words, the DIB and the resultant personality description were overwhelmingly rated highly for accuracy in revealing personality.
Now for the interesting point:
One and the same "personality description" was given to all the students. It had nothing to do with how students had responded to the DIB, which was a mere procedural ruse. It was a piece of fixed, generic description. Yet the students were impressed by its insight into their personalities.
Forer's results have been reproduced and confirmed by subsequent experiments; thus, there is little probability that his sample of subjects were any more gullible than most people. The fact is that if a one-size-fits-all personality description is given to people under the pretense of being a response to their specific individual personality, the vast majority of them will be impressed by its accuracy.
So to make a credible claim that astrology is able to identify specific personality traits, you will need to show that the results go beyond what can be explained by the Forer effect. So far as I know, no one has ever done this.