Dreams could be a dramatization of your fear ,a fantasy of your hope or a spiritual travel in unknown worlds of different dimensions.
Symbols in your dream are specific for you, as you are unique, also are your symbols. For example , the meaning of a car in a young boy dream or an old woman dream or a racing car driver or an ill man or a working mother ,never have the same meaning. The time of your dream differ, your culture, your background ,your surrounding environment are effective also repetition of the same dream could be an encrypted message.
So generalizing interpretation of dreams is not very accurate.
Why we dream is still one of the behavioral sciences' greatest unanswered questions. Researchers have offered many theories—memory consolidation, emotional regulation, threat simulation—but a unified one remains, well, a pipe dream. Nevertheless, people continue mining their nighttime reveries for clues to their inner lives, for creative insight, and even for premonitions.