Reading across a long illness — not a short illness but a sustained period of being unwell — produces a particular relationship with books. You're dependent on them in a way that healthy readers aren't. They're one of the few things you can do. The books accumulate a weight of association that persists long after recovery.

I read most of Patrick O'Brian's Aubrey-Maturin series during a year when I was recovering from something and couldn't work at full capacity. The sea voyages and the friendship between Jack Aubrey and Stephen Maturin became a kind of parallel life — more physically active than my own, more adventurous, accompanied by the best kind of description of what friendship can be.

O'Brian's treatment of friendship is the best in the language. Aubrey and Maturin are different in almost every dimension — temperament, politics, vocation, relationship to violence — and the friendship is precisely about the respect that difference creates rather than the comfort that similarity creates.