One of my favourite cartoons is of the owl and the pussycat going to sea in their pea-green boat. The caption is the owl’s guilty admission: ‘I’m afraid there have been… other cats.’ Caleb Carr, in this memoir of his own love affair with a pussycat, is straightfaced: ‘I should own up to the fact that I’d had similar relationships with other cats – even (and in some cases especially) cats who were not mine.