Your brain does a lot of processing of information when you're asleep, and it is also "programmed," as it were, to do a big data dump of unimportant stuff from the cache overnight. Forget walking to the curb to pick up the newspaper, what you had for lunch, what the traffic looked like when you drove the kids to school. No longer needed, unless you work to retrieve it and store it elsewhere. Brains aren't computers, quite, but there is research that shows why a good night's sleep is so important to letting the brain reset itself with the proper kinds of sleep.

SRS