The Door by Magda Szabó:
In my student days, I detested Schopenhauer. Only later did I come to acknowledge the force of his idea that every relationship involving personal feeling laid one open to attack, and the more people I allowed to become close to me, the greater the number of ways in which I was vulnerable. It wasn’t easy to accept that from now on I would always have to consider Emerence. Her life had become an integral part of my own. This led to the dreadful thought that one day I would lose her, that if I survived her there would be yet another addition to those ubiquitous, indefinable shadow-presences that wrack me and drive me to despair.