Bill Gates dropped out of college because he saw a digital revolution happening and he wanted to help shape it. He and Paul Allen went on to co-found Microsoft and the technology they created was fundamentally transformative. "The chance to be part of the software revolution empowering people was the biggest thing I have gotten to do," he reveals in a reddit "Ask me Anything." Today's graduates can make a similar mark on society, according to Gates. He sees three areas as having the most opportunity for impact :

1. Artificial intelligence "We have only begun to tap into all the ways it will make people's lives more productive and creative," he says. 2. Energy "Making it clean, affordable, and reliable will be essential for fighting poverty and climate change," according to Gates.

3. Biosciences The field is "ripe with opportunities to help people live longer, healthier lives," says Gates.