How much meaning do dreams REALLY hold?

There are different type of dreams due different reasons. The dreams will come and reflect our desires which consciously imprinted in our sub conscious mind. The others thought force might mae us to dreams. Some very very old one, many many generation earlier people got the experience which genetically cary forward through parents will come as dreams. Many many generation ago the uncivilized living condition in the forest, sleeping on tree to escape from the animals and fell down experience will come as dreams now. So people even fall down from the bed due to dreams. Most of the time our experience will come as dreams. Even indigestion also cause for dreams.