Bill Gates has made it a tradition to share his favorite reads on his blog, Gates Notes. Every year, he rounds up a selection of titles you may enjoy over the summer. The underlying theme of Gates' 2018 summer book list is that they all "wrestle with big questions," the self-made billionaire and Microsoft co-founder writes. "What makes a genius tick? Why do bad things happen to good people? Where does humanity come from, and where are we headed?" While the content is heavy, "all these books were fun to read," he says, "and most of them are pretty short." Consider adding these to your summer book list:

"Leonardo da Vinci" by Walter Isaacson

Isaacson's biography of Leonardo da Vinci "helps you see him as a complete human being and understand just how special he was," Gates writes. "He came close to understanding almost all of what was known on the planet at the time." While the Renaissance man is best known as a painter, da Vinci's interests ranged from human anatomy to theater. "When you look across all of Leonardo's many abilities and his few failings, the attribute that stands out above all else was his sense of wonder and curiosity," says Gates. "When he wanted to understand something … he would observe it closely, scribble down his thoughts, and then try to figure it all out." Gates is also a fan of Isaacson's biographies of Albert Einstein and Steve Jobs. Read Gates's full review of "Leonardo da Vinci."

"Everything Happens for a Reason and Other Lies I've Loved" by Kate Bowler

Bowler, a professor at the Duke Divinity School, was 35 years old, happily married and raising her young son when she found out she had stage IV colon cancer. "She sets out to understand why it happened," writes Gates. "Is it a test of her character? The result is a heartbreaking, surprisingly funny memoir about faith and coming to grips with your own mortality." Read Gates's full review of "Everything Happens for a Reason and Other Lies I've Loved."

"Lincoln in the Bardo" by George Saunders

"I thought I knew everything I needed to know about Abraham Lincoln, but this novel made me rethink parts of his life," says Gates of Saunders' award-winning novel, which blends Civil War history with fantastical elements. "It's basically a long conversation among 166 ghosts, including Lincoln's deceased son. … This is one of those fascinating, ambiguous books you'll want to discuss with a friend when you're done." Read Gates's full review of "Lincoln in the Bardo."

"Origin Story: A Big History of Everything" by David Christian

Historian David Christian's book takes you through the nearly 14 billion years of what we've come to know as "history," starting with the big bang and ending with today's complex societies and the future of humanity. "Understanding where humanity comes from is crucial to shaping where we go next," says Gates, who is also a fan of Christian's online course "Big History." "'Origin Story' is an up-to-date history of everything that will leave you with a greater appreciation of our place in the universe." Read Gates's full review of "Origin Story: A Big History of Everything."

"Factfulness" by Hans Rosling