Granted, I know very little about how brain work, but assume that general principle is dynamic building network between small elements in the brain which is aff

Granted, I know very little about how brain work, but assume that general principle is dynamic building network between small elements in the brain which is affected by different signals (which can come from both outside receptors, or could be generated by brain itself?).. So... Can someone explain in simple words why human brain _need_ to sleep to consolidate memory? What is memory? This is not like RAM in my desktop where you need to do map reduce to aggregate information... This is state of network which is constantly and dynamically changes..