sorry for DP, but I actually remembered my old Psych professor in my Learning and Behavior class last year that sleep will always aid in memory. Have you ever sleep deprived yourself for 2 days? I have. It's not pretty and normally, you shouldn't do it especially if your wanting to remember things.

Someone in that class did a small study that if you study for a test all night with no sleep so you can remember the information, you only remember the last thing you read and failed. If you study all evening with sufficient sleep (6-8 hours) they did much better on the test.