I recently begun reading I AM LEGEND, I really like it. I think Robert is extremely smart and knows how to live in a environment like he is in and will survive because he takes care of all of the weaknesses and isn't lazy at all he works hard to survive. I don't really get how the zombies know him though, because they said his name and got inside his head but how would they do that when there infected I wouldn't think they would be able to talk.
                      I think I have been in some situations where I have felt like Robert because he's very lonely and isolated he doesn't have much to do other then work eat and sleep and the same routine can get nerve racking after a while especially when they get inside your head and tourment you then it would be easy to become physco and just completely lose it.