If you find yourself anxious a lot, you're not alone. "The human mind wants to worry," writes Bill Gates on his blog, Gates Notes.

These days especially, there are plenty of "reasons for concern," he says, including terrorism, climate change, privacy breaches and the rise of artificial intelligence.

To curb or otherwise cope with those tensions, the Microsoft co-founder and avid reader recommends Noah Harari's new book, "21 Lessons for the 21st Century."

As Gates learned from Harari, "The trick for putting an end to our anxieties, he suggests, is not to stop worrying. It's to know which things to worry about, and how much to worry about them."

"But his big idea boils down to this: meditate," continues Gates, who recently picked up meditation as a regular habit. "Of course he isn't suggesting that the world's problems will vanish if enough of us start sitting in the lotus position and chanting om. But he does insist that life in the 21st century demands mindfulness — getting to know ourselves better and seeing how we contribute to suffering in our own lives.

"This is easy to mock, but as someone who's taking a course on mindfulness and meditation, I found it compelling."