Imagine you came across this ad.

Scientists have discovered a revolutionary new treatment that makes you live longer. It enhances your memory and makes you more creative. It makes you look more attractive. It keeps you slim and lowers food cravings. It protects you from cancer and dementia. It wards off colds and the flu. It lowers your risk of heart attacks and stroke, not to mention diabetes. You’ll even feel happier, less depressed, and less anxious. Are you interested?

It’s not a tea cleanse or a keto-diet, but sleep. I’ve just read Why We Sleep, a book by Professor Matthew Walker, a professor of neuroscience and psychology at Berkeley. He outlines the research supporting these claims. Despite the fact that’s we’ve not yet finished May, I’m convinced Why We Sleep is the most important book I’ll have read this year.

“I’ll sleep when I’m dead,” is a mantra I picked up and adopted at some point in high school and carried through to my first job as a software engineer. End result: in the emergency room with pneumonia on Christmas Eve. Secondary result that is much harder to quantify: enormous technical debt from bad judgement!

It’s one thing to be told that sleep is important. It’s another entirely to read about the experiments that prove the performance gains of people who sleep enough and well. And enough isn’t 4 or 5 or 6 hours. Though some subset of people do benefit from a genetic mutation that requires less sleep, that population when rounded is zero. Most people need at least 7 hours, consistently.

How impactful is a lack of sleep? If you sleep between 5 and 6 hours, your chances of suffering an accident in your car double. If you sleep 4-5 hours, they quadruple and anything less than four hours increases the odds by an order of magnitude. Drowsy driving accounts for more fatalities on US roads than drugs and drinking combined.

As I read this book, I asked myself: Would I make a $1M investment in the stock market after a few glasses of wine? Would you? A $1M investment for a venture capitalist might be a marketing campaign for another business, or hiring a VP Sales and four account executives for a startup for a year.

We make these types of decisions (and smaller and larger ones) frequently. Sleep is a key ingredient to ensuring we’re making the right call.