Getting a good night's sleep is one of the best things you can do to improve your health and mood. That sleep is crucial for us to survive and thrive is a scientific certainty, but there is so much that we don't know about it. Still, some things have been ascertained through years of studies (although most of what has been learned about sleep has been discovered in the last 25 years!)

Check out these fun sleep facts:

1. Napping is completely natural: mammals are physiologically programmed to feel extremely drowsy around 2 am and 2 pm. So if you're able, go ahead and take that catnap in the afternoon with no regrets. Just one word of warning – if you nap for longer than 45 minutes but less than 90 minutes, you will most likely wake up in a fog as you'll be waking up in the middle of your sleep cycle. (one sleep cycle is 90 minutes)
2. Not getting enough sleep can lead to disruptions in diet. People who aren't sleeping enough are more likely to eat more thanks to their leptin levels falling, promoting an increase in appetite. (Leptin is a hormone that helps regulate the appetite)
3. Sleeping less than 7 hours a day on average makes you three times more likely to catch a cold. So it's especially important to get enough sleep during the cold and flu season!
4. We spend about one-third of our lives sleeping…about 25 years!
5. Your body may be resting during sleep, but your brain is not! The brain moves between REM (rapid eye movement) and non-REM phases.
6. Dreaming is thought to be how your brain sorts out any unresolved issues before filing them as memories. Therefore, recurring dreams generally happen when you are preoccupied with something and have trouble letting it go.
7. Unsurprisingly, humans are the only animals that willingly put off sleeping.
8. Does everything seem funnier or wacky when you've been awake for a long time? Staying awake for 16 hours straight decreases your body's performance and gives you comparable feelings to having a blood-alcohol level of .05% (the legal limit is .08%). Just another reason you should NEVER drive when you're feeling exhausted.
9. 75% of people today dream in color. Before color television became widespread, only 15% of people did.
10. The current record for the longest period of time without sleep is 264.4 hours (about 11 days). We wouldn't recommend trying to beat this record, as it resulted in hallucinations, concentration, short-term memory lapses, and paranoia during the period of staying awake.