Uncovering and explaining how our digital world is changing — and changing us.

Alexis Ohanian recently joined Y Combinator as a partner. So I took the opportunity ahead of the seed accelerator’s famous Demo Day — which happens Tuesday in Silicon Valley — to talk to him about a wide range of topics, including what he is interested in investing in.

The high-profile Internet entrepreneur is, of course, the co-founder of Reddit, the social platform that was created in 2005 as the “front page of the Internet,” grew large and was eventually sold to Condé Nast.

Ohanian also launched travel site Hipmunk and social enterprise effort Breadpig. He’s a big advocate of the open Internet and an active angel investor as well.

And Ohanian recently wrote a book, titled “Without Their Permission,” about his life as an entrepreneur. Although he only recently turned 30, it is a primer for those even younger to see innovation as a reachable goal. His book tour, in fact, was mostly aimed at college campuses.

Here he is in the video interview I did with him, in which he explained why he can no longer party like a student: