If you want to remember something, just sleep on it as scientists say dreaming can help improve your memory and make you a better problem solver.
Researchers at the University of California found that people who enjoy a dream-filled sleep are significantly better at recalling information and making links between facts when they wake.
However, they suggested that recharging with a shallow nap offers no such mental boost, the Telegraph reported.
The findings add to the growing body of evidence that Rapid Eye Movement (REM) sleep -- the stage of slumber when our most intensely remembered dreams occur -- is crucial to the brain's ability to lay down and consolidate memories.
According to the scientists, an average night's repose includes four or five spells of REM sleep, but these bursts tend to be lengthier towards the end of the night.
This means that adults who get less than the recommended seven to eight hours of sleep a night may be damaging their mind's ability to form strong memories.
Dr Sara Mednick, a sleep researcher at the University of California who led the study, said: "REM sleep is important for pulling together all the information we process on a daily basis and turning it into memories we can use later.
"This helps us to understand more about the benefits of sleep and to help people maximise their sleep schedules for optimal productivity and memory retrieval."
Although REM sleep is not classified as a type of deep sleep, the scientists said, it is only reached after the brain has passed through deep sleep stages.
For their study, the researchers recruited a group of volunteers, who were shown combination of three words -- such as "cookie", "heart" and "sixteen" -- and asked to find another word that can be associated with all three words.
In this example, the answer would have been "sweet".
Participants were tested once in the morning and then given the same task again in the afternoon. In between, some were allowed a nap with REM sleep, some a nap without REM sleep, while the others had a quiet rest period.
It was found that the quiet rest and non-REM sleep groups showed no improvement in their test results, but the REM sleep group improved on their morning performance by an average of almost 40 per cent.