Her lover, the photographer Tom Groenendaal, tells her that her life is like a ‘bloody awful book by one of those women who have studied philosophy but can’t get a single sentence down on paper.’ The author also puts the ironic explanation of the title into his mouth. For him, people with a hobby are people who think that life can be made to correspond to a sound theory. Lilly’s fascination irritates him, although, ironically enough, it is he who aroused her interest in Hammerson. Van Brederode strips the story of all gravity, telling it ironically.

Despite the humour, Lilly nevertheless runs away with the rather vague ideas of the Norwegian philosopher, who bears some resemblance to Kierkegaard. Each chapter starts with an extract from Hammerson’s work, which is subsequently analysed, so that a picture gradually emerges of his views on ideology and actuality, art and life. Van Brederode often present this in the form of a monologue intérieur, in which Lilly’s associations, thoughts and feelings take form. She attempts to live according to Hammerson’s ethics, which promote a pure existence, focused on the inner being, removed from life and preferably celibate - ideas that gain a grip over Lilly partly because, after two miscarriages, she feels unfit for motherhood. Nothing comes of her other dream, that of becoming a writer, either. Just how far Van Brederode puts the philosophical pretentions of her main character into perspective becomes clear at the end, where the novel actually blows up bizarrely and excitingly. Lilly has been unintentionally deceived about Hammerson by her lover, Tom, who in turn, becomes painfully aware of this.