Keep in mind this was written in 2007. I don't think all of that stuff is irrelevant by any means, though. Nine years later, the list might look somewhat differ

Keep in mind this was written in 2007. I don't think all of that stuff is irrelevant by any means, though. Nine years later, the list might look somewhat different, but his point is that it's an indicator of intellectual curiosity, not things that are directly practical for the job the employer is offering.