Bill Gates
Billionaire philanthropist Bill Gates attends the World Economic Forum annual meeting in Davos, Switzerland, Jan. 19, 2017. Reuters

If you can’t personally see Microsoft co-founder Bill Gates give a commencement speech, you can check out the advice he dispensed in a series of tweets aimed at incoming freshmen Monday.

The philanthropist revealed the fields he would study if he was enrolling in college now.

“AI [artificial intelligence], energy and biosciences are promising fields where you can make a huge impact. It's what I would do if starting out today,” Gates said.

Read: What Will War Look Like In The Future? Terrorists Could Kill Millions With Biological Weapons, Bill Gates Warns

Artificial intelligence is not a surpise since Gates has previously has talked about AI, especially robots. In February, Gates suggested robots should get taxed just like humans. He said the tax system on automated labor should mirror what the government does in taxing a person's wages to fund social programs.

“Right now if a human worker does you know, $50,000 worth of work in a factory, that income is taxed,” Gates told Quartz. “If a robot comes in to do the same thing, you’d think we would tax the robot at a similar level.”

Bill Gate’s Big Regret

Gates, who started the Bill & Melinda Gates Foundation along with his wife, also talked about his “one big regret.”

“I also have one big regret: When I left school, I knew little about the world’s worst inequities. Took me decades to learn,” Gates tweeted.

The couple launched the foundation in 2000. Since then, the organization has worked to help people dealing with hunger and poverty. The foundation also works to advance science and technology in developing countries, plus other projects.

Gates added he is optimistic about the younger generation.

“You know more than I did when I was your age,” he said. “You can start fighting inequity, whether down the street or around the world, sooner.”

Read: Secrets Of Success From Bill Gates: Billionaire And Former Microsoft CEO Answers Reddit Users' Questions

Gate’s Believes the World is Getting Better

Gates also recommended a book by Harvard cognitive scientist Steven Pinker “Better Angels of Our Nature,” which explains why violence has declined.

@SAPinker shows how the world is getting better,” Gates said. "Sounds crazy, but it’s true. This is the most peaceful time in human history.”

Gates said knowing the world is getting better will make you want to “spread the progress to more people and places.”

“This is an amazing time to be alive. I hope you make the most of it,” Gates said ending his advice tweet series.

Here’s the full thread of Gate’s advice: