Not all Gemini people are generous.
And most are not narcissists.
The problem here is that you are using the SUN sign (when you look up the month-day of birth, what you find is the position of Sun only).
And since Sun is only ONE out of 40-50 factors in the unique birthchart of any individual, you don't get much real information from JUST the sign that Sun is in.
Don't try to make any rules about how a "sign" is or isn't. It won't hold up under examination. And NO real astrologer uses Sun sign astrology.
“Many people think that astrology is the Sun-sign columns found in every newspaper and online news media sites. Nothing could be further from the truth. That’s not astrology, that’s entertainment, which is what’s often stated in the fine print beneath astrology columns. Unfortunately, Sun-sign columns are one of the most persistently misleading representations of astrology. “
(Dorothy Oja: “What Astrology is and isn’t”)
In case you want to use astrology, find out your exact time of birth, and enter that, along with the full date of birth (year included) and the place of birth. The internet abounds with websites that will calculate the birthchart of anyone for free ... as long as you have the date/time/place of birth.
I recommend alabe.com, but any website will do.