There had to be one universe — just this one — where we don’t end up together. Here and now just happens to be it.

Why is love intensified by absence?

How we need another soul to cling to, another body to keep us warm. To rest and trust; to give your soul in confidence: I need this, I need someone to pour myself into.

I feel bound to mention that lots of universes also have wars, and yet we are the Warverse. Sophie and I also teach at Cambridge in many quantum realities, but there is only one Cambridgeverse. And while absolutely every dimension discovered so far has an ocean, we have nonetheless designated an Oceanverse. In other words, my darling girl, the names are all sort of arbitrary and rubbish and it’s not worth making a fuss over, is it?

The multiverse, she said, was like an old library whose shelves were packed with books arranged by a cataloguing system that ranked them according to similarity, each book containing within its covers a story that varied only slightly from the stories of its immediate neighbours, but by increasing degrees from those of increasingly distant books.

I know you are mine,not in my life but in my memories