Writers are obligated to live for themselves

"And yet I had not been wrong, perhaps, after all, in sacrificing not only the vain pleasures of the world but the real pleasure of friendship to that of spending the whole day in this green garden.  People who enjoy the capacity—it is true that such people are artists, and I had long been convinced that I should never be that—are also under an obligation to live for themselves. And friendship is a dispensation from this duty, an abdication of self.  Even conversation, which is the mode of expression of friendship, is a superficial digression which gives us no new acquisition. We may talk for a lifetime without doing more than indefinitely repeat the vacuity of a minute, whereas the march of thought in the solitary travail of artistic creation proceeds downwards, into the depths, in the only direction that is not closed to us, along which we are free to advance—though with more effort, it is true—towards a goal of truth.  And friendship is not merely devoid of virtue, like conversation, it is fatal to us as well. For the sense of boredom which it is impossible not to feel in a friend's company (when, that is to say, we must remain exposed on the surface of our consciousness, instead of pursuing our voyage of discovery into the depths) for those of us in whom the law of development is purely internal—that first impression of boredom our friendship impels us to correct when we are alone again, to recall with emotion the words uttered by our friend, to look upon them as a valuable addition to our substance, albeit we are not like buildings to which stones can be added from without, but like trees which draw from their own sap the knot that duly appears on their trunks, the spreading roof of their foliage."
Marcel Proust, Within a Budding Grove