On some topics, I have a different perspective just because I am older than most people here, so I remember history that other participants have to read about. Genetics research to be a responsible popular author about that research is part of my work, so this topic was work-related. I got lucky over the weekend, because I had just looked up the human population research articles to get ready for some contentious editing on Wikipedia, and thus all of the sources were at hand. Some of the other topics I comment about are also work-related, or related to my former work or my higher education degrees (neither of which were in computer science).
Dr Ray Stantz: You never studied.
(I think the answer is simple: he has an interest in all those things, so he follows them).
I was consulting (software) at a client site and one of the employees at the client remarked that I seemed to know everything about everything. I just replied that it was a trick - I only talk about the things I'm informed on, and when a question came up on a topic I didn't know anything about, I just redirected the conversation back to my expertise. I had a hammer and worked hard to make everything a nail. :)
How on earth are you well informed on so many topics spanning different fields of science and literature? Your comments are amazingly well informed, and I would like to know how you do it.