I'm not a self-centered asshole. I don't think any writer is. Many are assholes, I'm sure--or translate as such into human terms--but not self-centered. It's not a martyr complex; it's the plain truth: no one who was actually self-centered would treat himself the way a writer treats himself, alienating personal relationships and then dissecting them in print; abjuring sleep and calm: living on an edge, in constant danger of falling, for no better reason than to be able to see down, in addition to being able to see up and around.
Why do we do it? Why do we hurt ourselves? It's because we are locked boxes with precious things inside of us that can only be accessed by tearing through the shell. But it's something that we're not alone in doing--authors. Everyone cracks the shell to get at the seed, and the seed, of course, is time--the sheer beautiful paradox that we don't have too much time alive and don't know where we go after that. The signature difference between an artist, a laborer, and an entrepreneur is that, whereas a laborer uses his time for work directly, an artist divides his time between introspection, that is, plumbing the nature of his own time on Earth, and the creation of art--which is little more than a by-product of that introspection. An entrepreneur uses his time directing the use of others' time, including that of artists.
That doesn't account for the people artists hurt in their pursuit of self-immolation. Very little accounts for, or explains, or justifies, the hurt endured by the people with whom an artist associates. The only way I've ever seen it explained is in terms of present and future--the way people account for someone like Winston Churchill saving England and the free world, but doing a shit job of raising his children. The former was very noble and wonderful, but there's no denying that children would prefer, in the final analysis, to be raised by competent parents.
Of course, this will all seem hilariously ironic in a few dozen years if I don't make it as an author.