I obviously have all the personalities of Gemini, but why am I a cancer when dating?

A person's personality can't be simply considered according to the constellation. His personality is usually inherited (a small part) and changed by experiences in life and society. It cannot be said that people born in cancer must have the character of cancer, nor can it be said that people born in this period also have the same character. Besides, has this ever happened in reality? Don't be bound by constellations, for example, I don't care about this either. I'm a cancer, too, but I usually say I'm made of cells.