There is new evidence indicating sleep improves your ability to recall information.
There has been an ongoing debate about whether sleep aids a type of memory called declarative memory, which allows you to recall learned facts and events.
A study examined 60 people who were required to memorize 20 paired words, and then tested on them 12 hours later. Some were also taught an additional 20 paired words as a distraction.
Both those in the "distracted" group and the "non-distracted" group did better if they were allowed to sleep between learning and testing. This could mean that sleep is not an inactive state, but an important period for the consolidation of memories and other brain functions.