[karaterobot]

The core advice is to figure out what you want to do in your career, and choose an academic path that supports that. He's pointing out that the mistake people make is to choose an academic subject and assume there'll be a job that maps perfectly to that subject, when there usually isn't.

The issue I have with it is that when I was in college, one of the few things I knew least about is what I wanted to do with my life.

[actusual]

I was the other way. I knew exactly what I wanted to do, but my university had extremely competitive programs, so getting into the CS program was nearly impossible, even if you were already admitted to the university.