These theories don't really feature a lot in my life because I try to avoid them to stop being depressed, but whenever I hear about one of them it completely blows my mind. I'm not sure at all if this counts, but I came across this one a few weeks back and it made me so freaking depressed I wanted to cry:
http://www.smbc-comics.com/index.php?db=comics&id=2643
I will never ever read Garfield the same way again.