Scientists have known for decades that the brain requires sleep to consolidate learning and memory. Sleep is beneficial for a wide range of learning and memory. Humans are designed to spend about one-third of our lives sleeping, which adds up to about 8 hours a night.
By the time you are 60, ideally you will have slept for 20 years—5 of those years will be spent in REM sleep, dreaming. This ratio of one hour of sleep for every two hours of wakefulness is hardwired into our biology and necessary for both our survival and optimal performance.
Take a look at this interesting information, there is a strong argument that supports the following notion: learning + sleep = better retention of skills.