When his parents split up, they also split up the children. The father took the older two children, a boy and a girl, and the mother took the younger two, also a boy and a girl. So they grew up more or less separately, in very different households and different places. The father was a successful journalist and lived in glamorous places like London, Paris, and New York. The mother had to go back to work and became an unsuccessful librarian living in an English-speaking enclave of Montreal, among other places. The siblings were more like cousins than siblings.