First of all, I am Capricorn. People in this constellation generally don't directly tell others what they think. They tend to keep their thoughts in their stomachs. They have many secrets of their own, so they tend to let people guess them. Over time, they will have fewer and fewer friends. After all, everyone wants to make a friend who talks about everything, but Capricorn is often not very real to people. They are often happy, but they have it in their hearts.
Then there is Scorpio. People in this constellation are also very introverted. Although they seem selfish, it's because they have their own ideas. Their ideas are unique, so many people don't understand them. But they often don't show their unhappiness, and often hide their thoughts in their hearts, so no one knows what they are thinking. Over time, they will feel that fewer and fewer people understand them, and they will only feel heartless, so they will slowly.
Then there is Aquarius. People in this constellation are also very lonely, and this constellation is naturally silent. They are often weak in interpersonal communication and cannot express their views, so people often can't see through them. Over time, they don't like to express themselves, that is, they are more introverted and even become unwilling to make friends. Because making friends may be a burden to them, they have fewer and fewer friends.
Of course, this is just my personal opinion. I hope you can add more.