Chinese quiz?
1. This is not a part of any formal Chinese language curriculum, nor culture or history curriculum.
2. The "outer personality" thing was invented in the West. It doesn't belong to authentic and genuine Chinese culture/astrology.
3. Imagine this: if you have outer personality, inner personality, and two other personalities, do you have split personality?
We do teach 10 heavenly stems and 12 earthly branches. They form a cycle of 60 counts. They are used to denote lunar calendar of the year, month, day, and time. This is for thousand of years before there is Western calendar.
In school, there is also mentioning as part of culture curriculum for the use of 12 animal signs. This is indeed a part of the genuine culture for that the 12 animal signs were mapped to the 12 earthly branches. A few hundred of years ago, if you mention to someone else your sign, the other person would immediately know your age. There is also a shallow level of superstition.
For people who have special interests in learning Chinese astrology, they will need to find sources outside of the regular school.
For the year/month/day/time component, each component has two elements which forms one pillar. There are 4 pillars and 8 elements. Plus yin/yang, gender, and the season, the interactions of the elements and the balance, we can tell one's fortune trend.
This is call Ba Zi. In Ba Zi, there are 520,000 combinations. Ba Zi is one of the two mainstream Chinese astrology approaches.
You've been given incorrect information that is not authentic and genuine Chinese astrology.