We had a cat when I was very young. He was a skinny, long-limbed cat with no sense of personal space and a loud, grating voice. If you sat still the cat was there, in your face, demanding entertainment. The cat was convinced we were only there to serve him. If he didn't need anything from you, you didn't exist.

One summer when I was eight, I spent two weeks with my cousins. The cat ignored me for three days when I came home, apparently irritated that I failed to be where he wanted me to be.

I was trying to read – working my way through a set of mystery novels and short stories I'd found in "my" room. I was trying to read because I was finding it very difficult because Sherlock was sitting next to me, his spine pressed against my left side, subtly pushing me into the right arm of the sofa.

"What year were you born?" I asked.

"Why?"

"Just wondering if you're the reincarnation of my old cat."

"Maybe. What was his name?"

"Oswald."

"Oswald? That's a stupid name."

"Oh really, Sherlock?"

"Touché. " A pause. "Tell me about your cat."

"He was... you know. He was a cat. Very catlike."

"We were never allowed pets."

"Probably afraid of what you'd do to them in the name of science."

Sherlock bristled, apparently remembering our argument from a few days before. "I am capable of putting my analytical impulses on hold."

"Of course you are," I said soothingly, reaching up to scratch behind his ear. Sherlock was immediately mollified. "Oswald liked that, too." I teased.

"Did Oswald also like having his stomach rubbed?"

"Hated it. He'd have your arm off if you tried." I took the hint and – despite the awkward angle – ran my hand along Sherlock's stomach and ribs. Still too thin, I thought. Once we're home I'll start after him about eating better.

"What did Oswald like?"

"He liked hearing me talk. I'd do my homework by telling him what I was doing. Read aloud. Work out my maths by talking to him."

"See? Thinking out loud helps."

"He also really liked crumpled up paper. Shall I crumple some paper for you to chase?"

"Ha. Ha." Sherlock crossed his arms over his stomach, stilling my hand. I went back to my book.

After a while Sherlock spoke again. "Did you love him?"

"Suppose so, yeah. I mean, he was a cat, so... as much as you can love a cat without it being creepy."

"Ah." Said Sherlock.