How do they do it?

How do people sit and watch T.V. all day long? Yesterday afternoon I spent 6 hours straight watching a marathon of Psych episodes. (The marathon was actually 7 1/2 hours long, but I missed the first 30 minutes and the last hour.) Anyway, before I had even sat through the first 4 hours I was getting a headache, and by the time I stopped watching I just felt totally "out of it". Now don't get me wrong, Psych, rocks, or else I wouldn't have watched them. I had never seen it before, but it turned out to be a really great show. I would recommend watching it, just not for 6 hours straight. Television can be a good and enjoyable thing, but I think I need to remember to partake of it in moderation from now on.