I enjoyed this little post as I really related to what he wrote, and the graphs were funny and accurate, but I think he put a bit too much emphasis on "unhappy", which I believe is not accurate. I, and other entrepreneurs I know, are not Always Unhappy. It's more like Never Happy For Long. During the upswing on the graph, I am extremely happy! Ecstatic! But then even though business (let's say) has doubled almost overnight, a month or so will go by with no new growth, and I'm just miserable, wondering how I can make something happen.
I would chalk this up to the human tendency to always want the next thing, or always want what one doesn't have. And that personality type I think is a perfect fit for a self driven risk taker entrepreneur types.