This has not been proven. We need to learn to listen to them. Often dreams are strange in that time, space distance, and events are distorted. We do know that you are more likely to remember early morning dreams than others. Some people claim they have control over their dreams although this has never been scientifically proven.
Some people dream in color, others in black and white.
Some people claim they can see the future in their dreams. This has never been scientifically documented. Many people believe that there is a lot of symbolism in our dreams. The Induction Process Requires trust, concentration and something to focus on in order to produce a trance. The power of suggestion is a crucial part of the process.