As a part of your everyday survival skills the capacity to predict the future is a well developed part of life. So much so you often fail to notice doing it. For instance when crossing a road you quickly take in factors related to sounds, car speeds, and your own physical condition, and predict the likelihood of being able to cross the road without injury. Based on information gathered, often unconsciously, we also attempt to asses or predict the outcome of relationships, job interviews, business ventures, and any course of action important to us.
You have millions of possible intuitive insights
Because the unconscious is the storehouse of millions of bits of observed information, and because it has a well developed function enabling us to scan information and predict from it, some dreams forecast the future. Such predictions may occur more frequently in a dream rather than as waking insight, because few people can put aside their likes and dislikes, prejudices and hopes sufficiently to allow such information into consciousness. While asleep some of these barriers drop and allow information to be presented.
Reaching for More
Some precognitive dreams go beyond the ability to predict from information already held. So far there is no theory that is commonly accepted that explains this. A not too bizarre one however, is that our unconscious has access to a collective mind. With so much more information available, it can transcend the usual limitations when predicting from personal information. The speculative side of modern physics suggests an extension to this in saying the origins of our being lie beyond space and time. If we touch this aspect of ourselves, we may transcend our usual time-bound self, and see things in new ways – one of which might be precognition. See: ESP in dreams; Supersenses, Prediction. For any dreams of yours that appear to be predictive please see advice for predictive dreams.