“Human beings are the only species that deliberately deprive themselves of sleep for no apparent gain. Many people walk through their lives in an underslept state, not realizing it.”

That’s what Matthew Walker, a sleep scientist and director of the Center for Human Sleep Science at the University of Berkeley said while discussing the current state of sleep in America.

If you’re consistently getting less than 6 hours of sleep, you’re causing your body serious harm.

“Every disease that is killing us in developed nations has causal and significant links to a lack of sleep,” he says. “So that classic maxim that you may [have] heard that you can sleep when you’re dead, it’s actually mortally unwise advice from a very serious standpoint.”

In the far-ranging interview with NPR, Walker shares some of the latest wisdom and research on why we can’t sleep, how to get better sleep, and some fundamentals for improving the sleep you get.

If you’ve been following Joe for any length of time, you know this is one of his favorite “soap-boxes.” Sleep is when the body goes into repair mode. It’s when the brain cleans itself. It’s so very, very important to good health that it really can’t be overstated. Check out the videos below to learn even more about the importance of sleep and how you can improve yours naturally.