Why We Sleep: Unlocking the Power of Sleep and Dreams

It's a good reference about the science of sleep: our biological needs, what sleep does to our brain and, most importantly, what are the negative consequences caused by sleep deprivation.
Some things that I learned:
- Sleeping less than 7 hours a night is not enough. We should aim for 8 - 9 hours.
- Sleeping in on weekends doesn't make up for a whole workweek of lack of sleep.
- We should maintain the same sleeping routine throughout the week, including weekends.
- Insomnia in not the same as sleep deprivation.
- It is not recommended to take naps after 3pm.
- A sleep deprived brain has the same decrease in cognitive power than a drunk brain (being sleep deprived is like being drunk).
- Lack of sleep has a huge impact on our health, life expectancy, productivity and learning.