My first book is about twins who are attached: two people who are joined and can't escape each other.

I suppose that, for most of us, the fascination of conjoined twins is that such people can serve as symbols.

Conjoined twins are identical siblings who develop one placenta out of a single fertilised ovum. No cases of conjoined triplets or quadruplets have been documented.

What makes writing a memoir difficult is harder to quantify. Is it learning to know when you're ready to talk about something? Is it seeing the structure in a lumpen mass of fact? Is it finding out what you were really like as other people saw you? Yes to each.

I hold this to be the highest task for a bond between two people: that each protects the solitude of the other.

Honesty and loyalty are key. If two people can be honest with each other about everything, that's probably the biggest key to success.