Not sleeping well leads to a whole range of memory problems. During your sleep cycles is when the brain "consolidates" your memories. If you nightly sleep is too short, these memories don't form completely, leaving room for memory gaps and even false memories.

In a clever study, researchers had volunteers randomly put into an "awake all night group" or a "normal sleep group." In the morning they showed them lists of words. Then asked them to recall the words in the list. The sleep deprived people, essentially, made up more words than the well rested group. Interestingly, some of the sleep-deprived were more certain of their made-up words than the words that were actually on the list.

So if you are concerned about memory, are a student or just want to keep everything stright in your head it may be more important to sleep well than to pull an "all-nighter."

Tips for a Good Night's Sleep