How much hard time a dream?

Old it was thought that the dreams happened in flashs(fraction of seconds), today is known that they in the truth occupy real time in our mind, that is, happen in the same speed who we imagine to be living deeply them. A hard common dream of 10 the 40 min. Its plot always is related with in our fears, concerns, desires or things that are for happening. Some people imagine that they do not dream, what it is not truth, do not only remember themselves to have it done. This occurs because to remember a dream she is necessary to wake up at the moment where it happens.