It's not just you. Apparently billionaires and ex-presidents are also sitting at their desks daydreaming about summer vacation right about now.

First, President Obama offered five books he thinks make for perfect start of summer reading. Now Bill Gates is out with his annual list of reads to fill your beach bag or carry-on this summer.

But, as is usual with the Microsoft founder turned philanthropist, his selections aren't spy thrillers or whodunits. Instead, like many of the rest of us, Gates appears to be a little stressed about the state of the world this summer.

"None of them are what most people think of as a light read," Gates confesses in his blog post announcing his picks. "I've recently found myself drawn to books about upheaval (that's even the title of the one of them)--whether it's the Soviet Union right after the Bolshevik revolution, the United States during times of war, or a global re-evaluation of our economic system."

Maybe the theory is that reading about societies in turmoil makes your own worries seem less lonely. Maybe these books provide inspiration for solutions. Maybe Gates just can't focus on teen vampires or secret agents at the moment (though he's previously revealed he's a big fan of some lighter fiction titles).

Whatever the reason for his choices, Gates' list is perfect for those of us too preoccupied with the troubled state of the world to check out with a page turner this summer.

1. Upheaval by Jared Diamond

"I'm a big fan of everything Jared has written, and his latest is no exception. The book explores how societies react during moments of crisis," writes Gates. "It sounds a bit depressing, but I finished the book even more optimistic about our ability to solve problems than I started." Some reviewers are not as fond of the book as Gates, however, citing its many inaccuracies.

2. Nine Pints by Rose George

"If you get grossed out by blood, this one probably isn't for you," warns Gates before continuing: "But if you're like me and find it fascinating, you'll enjoy this book by a British journalist with an especially personal connection to the subject. I'm a big fan of books that go deep on one specific topic, so Nine Pints (the title refers to the volume of blood in the average adult) was right up my alley. It's filled with super-interesting facts that will leave you with a new appreciation for blood."

3. A Gentleman in Moscow by Amor Towles ?

This novel about a Russian count sentenced to house arrest in a Moscow hotel is apparently popular in Gates' circle. "It seems like everyone I know has read this book. I finally joined the club after my brother-in-law sent me a copy, and I'm glad I did," he reports, calling the book "fun, clever, and surprisingly upbeat" and "an amazing story anyone can enjoy."

4. Presidents of War by Michael Beschloss?

"My interest in all aspects of the Vietnam War is the main reason I decided to pick up this book. By the time I finished it, I learned a lot not only about Vietnam but about the eight other major conflicts the U.S. entered between the turn of the 19th century and the 1970s," writes Gates, who claims the book taught him lessons in "presidential leadership."

5. The Future of Capitalism by Paul Collier

Worried about how our current version of capitalism is playing out? It might surprise you to learn so is Bill Gates. "Collier's latest book is a thought-provoking look at a topic that's top of mind for a lot of people right now. Although I don't agree with him about everything--I think his analysis of the problem is better than his proposed solutions--his background as a development economist gives him a smart perspective on where capitalism is headed," Gates claims.