Gates took to Twitter on Monday morning, saying if he were just beginning his career today, he would pursue something in artificial intelligence, energy or biosciences, all of which are "promising fields."
He added that his biggest regret when he left school was that he didn't know enough about "the world's worst inequities," something that has now taken him decades to learn, he said.
Gate's gift to graduating students would be what he calls the most inspiring book he's ever read, Stephen Pinker's "The Better Angels of Our Nature."
"This is an amazing time to be alive," Gates tweeted Monday. "I hope you make the most of it."