The strangeness of Oe's A Personal Matter and what that may represent

Kenzaburo Oe's most famous work, his 1964 novel A Personal Matter, is strange on so many levels. It recounts the experience of a 27-year-old man, beginning on the day that his wife gives birth to their first child, a little boy with an extremely rare malformation, a gap in his skull where the brain had protruded forming what almost looks like a 2nd head. As the novel begins, a trio of doctors explain to the young man, named Bird (because of his birdlike appearance) inform him that the boy is sure to die and asking him for various permissions, notably transferring the child to a bigger and more equipped hospital so that doctors can learn about this rare occurrence. All of this trauma is made more terrifying and poignant in that most readers will surely know that this account is to a degree autobiographical; Oe has a son born with this condition who is still alive and although still suffering w/ many disabilities he has developed a successful career in musical composition. So w/ that knowledge, what do we make of the bizarre and self-destructive and even cruel behavior of Bird?: a recovering alcoholic, he goes on a series drinking binge (enabled by his father-in-law no less!), goes off to see his "girlfriend" (someone he sees about once a year it seems, and w/ who he had sex only once, way back in college days, who nevertheless takes him in, drinks w/ him, and philosophizes about death and resurrection), and over the first two days since the birth makes no effort to see his wife, to discuss this matter with her, and to console her (it's not clear that, 2 days after the birth, she knows anything about the boy's condition). So to what extent are these strange (to me) plot elements part of Japanese culture at the time (would it be typical for a husband to be away from the hospital and from his wife for days, for the parents and in-laws to be going about their lives and not close to the couple after the birth?); to what extent are these behaviors the weird and idiosyncratic behaviors of Bird and his family members; to what extent is this an indictment of the medical establishment then and later (the doctors and medical staff are almost entirely unsympathetic to any feelings Bird may have about his poor son and are far too quick to anticipate an imminent death), and to what extent if any does Bird's behavior serve as a painful confession from Oe, who may look upon his youth and this turning point in his life with some share and regret (for which he has more than made up over the course of his life)?