What does it mean when you die in all your dreams?

It means very little, and probably nothing whatsoever to you, when you die in someone else's dream. When death occurs in dreams, it is a metaphor representing significant change, such as the end of a career, graduation or divorce. At the end of the school year, many students have dreams of death simply because term is ending. More importantly, dreams are about the dreamer. So when you appear in someone else's dream, "you" symbolize some aspect of that other person. The link below provides additional examples and discussion about death in dreams.