Why You May Not Act Like Your Sun Sign
Probably most of the confusion about how you seem to have more traits of a different Sign (than the one those Sun Sign tables of dates is indicating you "should" be like) comes from having your Ascendant in a different Sign than your Sun Sign.
Your Sun Sign indicates how you are "deep down" - as in "character" and "sense of self" and "goals in life" and basic strategies for "BE-ing" and expressing your "Self" - while your Rising Sign indicates how you appear "on the surface" - as in "superficial style" and "mannerisms". The traits of your Rising Sign show in your outward appearance, personal style, little habits and quirks much more than your Sun Sign.
How you "appear" is not necessarily how you "are", and that is one manifestation of having the Sun and Ascendant in different Signs. You still "are" the way your Sun Sign qualities would indicate - you just may not "act" that way on the surface, if your Ascendant is in a different Sign. So you may actually "appear" more like your Rising Sign than your Sun Sign. It is not being "born on the cusp" that causes this - it is from having your Sun in a different Sign than your Ascendant.
As long as you keep in mind that the qualities and traits of the Rising Sign are only about "how you appear" on the surface to others, or how you unconsciously try to "act" in your personal interactions with others, you can read about the traits of your own Rising Sign simply by reading the many descriptions of the qualities of that Sign in the Sun Sign articles and
So if your Sun Sign is Taurus, but your Rising Sign is Gemini, then read about the Gemini Sun Sign to see how you "act" and "appear" to others who meet you in person. To put it simply, you are "a Taurus" who tends to appear and act like "a Gemini". Since adjacent Signs like Taurus and Gemini are always very different, people will be seeing Gemini traits in your outer appearance and style that are quite unlike what you would expect from someone with Sun in Taurus. If you honestly ask yourself if you actually LIKE to "be seen" as having some of the better Gemini traits like wittiness, writing and speaking and communication skills, great curiosity, and adaptability... the true answer will probably be that you do.
If you don't, then understand that you will be acting in some Gemini ways whether you realize it or not. Ask your friends if they see any "Gemini" traits in you. Do you gesture with your hands when you talk? Do you talk a lot more than the typical quiet Taurus? Do you like your habitual "routine" but sometimes get restless and bored easily? Do you like to stay home a lot but also need to get out sometimes to socialize and meet people? Do you sometimes have trouble finishing what you started? Those are NOT traits of the typical Sun in Taurus person. By the way, someone with Sun in Taurus can only have a Rising Sign of Gemini if they were born within a few hours after sunrise (but not before and not more than 4 hours after). The exact time frame will vary, but the earlier in Taurus you were born, the earlier it would have to be AFTER sunrise for Gemini to be rising.
Anyone who knows their TIME of birth can use this Rising Sign Table to estimate their true Rising Sign.
Your "Public Image"
You could call your Rising Sign traits your "personal style". It is seen by people who meet with you in person. But you also have another "image" which is not "personal" - your "public image" which is defined by your Midheaven Sign. The Midheaven is the Point which was directly overhead in the sky at the time and place you were born, and the Sign which contains the Midheaven is called your Midheaven Sign or Sign on the Midheaven. It has a lot to do with your career and your "true calling" in life - what you do in this world that fulfills you, whether you do it to earn a living, or do it for free as charity work or a public service, or do it as a pastime, recreation, or hobby.
The difference between your Rising Sign "personal style" and your Midheaven Sign "public image" is WHO perceives that image you project. Your Midheaven Sign shows how you are perceived by the general public, who do NOT know you personally. They define you by what you "do" in your career or in your community, by your "title" in a job you do, or "what you are known for" (such as the author of a book, an actor in films or TV, the cop on the beat, the person who works at the animal shelter). Your Rising Sign shows how you are perceived by the people who meet you for the first time and don't really know your "character" yet (your Sun Sign), or the people you personally meet in your everyday life in your neighborhood, at school, or social life.
If you want to know about your Midheaven Sign, you can assume that it is the third Sign BEFORE your Rising Sign. Start with your Rising Sign, skip the two Signs that come before it, and the next one will usually be your Midheaven Sign (though it is sometimes the one before that). You will know when you read about the qualities of that Sign in an article or book about Sun Signs. Most of the qualities of a particular Sun Sign will be similar to the qualities of that Sign when the Ascendant is in it (the Rising Sign) or the Midheaven is in it (the Midheaven Sign). You just have to relate those qualities not to your inner being (represented by the Sun), but to your outer "image".
Astrology Books About the Rising Sign
Two good astrology books about the Rising Sign and Ascendant which I can recommend are: "The Astrology of Rising Signs" by Carl Sargent, and "The Ascendant: Your Karmic Doorway" by Martin Schulman.
"What Sign Is My Rising Sign?"