dreams are what?

it is said that we have dreams because we desire. many a times our desires would appear full term in our dreams but never in real life. mind you i'm not talking about the erotic but more of our aspirations or rather things or people we can be with. even jobs. i know of some people who really wish to be pilots but for one reason or another they are not able to fulfill their dreams. we all know of people who wishes to be with someone but in the end things just do not work out. are dreams in a way, someting to quench our desires? dreaming is only one of the many sub-concious levels we are at. sometimes we even have dreams which are somehow able to foretell the future, deja vu anyone? till this day, nobody is able to curely describe the concept of deja vu clearly, with psychiatrists labelling it as a matter of coincidences. the human brain is indeed very complex.