Sara Mednick, PhD wants you to take a nap. She wrote a book about it (Take a Nap, Change Your Life). No, you don’t have to stop at 20 minutes:
Research shows longer naps help boost memory and enhance creativity. Slow-wave sleep — napping for approximately 30 to 60 minutes — is good for decision-making skills, such as memorizing vocabulary or recalling directions. Getting rapid eye movement or REM sleep, usually 60 to 90 minutes of napping, plays a key role in making new connections in the brain and solving creative problems.