You forget 90% of your dreams

After five minutes awake half the dream has been forgotten. In 10m, 90% is gone. The famous poet Samuel Taylor Coleridge woke up one morning after having a fantastic dream (likely opium induced) and began to describe his "vision in a dream", which is one of England's most famous poems: Kubla Khan. After having written 54 lines he was interrupted by an unwelcome visitor. Samuel returned to his poem but could not remember the rest of your dream. The poem was never completed.

Interestingly the author Robert Stecenson invented the story of Doctor Jeckyll and Mr. Hyde while sleeping. Frankenstein by Mary Shelley, was also the son of an author's dream.