You'll never believe these amazing facts about sleeping! Tell us which one you thought was the coolest in the comments below...

The longest a person has stayed awake is 11 days and 24 minutes. We bet they slept well after that!

2. Only one half of a dolphin's brain goes to sleep at a time... Must be why they're so smart!

3. Before alarm clocks, there were 'knocker ups' who went tapping on people's windows with long sticks until they woke up.

4. It's impossible to sneeze while you're sleeping. Wha?! Yep, fact!

5. Some otters hold hands while they sleep so they don't drift away from each other. So cute!

6. People sleep better when there is a new moon and worse during a full moon. No one really knows why this happens. Weird...

7. Many Tibetan monks sleep upright. They do this because it's an old Buddhist tradition.

8. Cats sleep for 70 per cent of their lives. Lazy, but super adorable!

9. Twelve per cent of people dream only in black and white, (but this number was higher before colour TV was invented!)

10. Within five minutes of waking up, you forget 50 per cent of your dreams.