String Theory explains this. You know, every element in our bodies was made inside an exploding star. We just borrow star dust until we die, and then we return it for something else to use. We're like vibrating strings. You know, notes of the cosmos, and each and every one of them have their own part of the song. You take away one part, that song changes, but the song never dies.
I have spent the past 30 years living like a nomad. I have done land mines, coups. I have been hijacked, and I've nearly drowned trying to help people. I've seen off two husbands, and somewhere out there is an adopted son who hasn't called me for six weeks. And if that's not enough, I was an air hostess in the early '80s. And trust me, compared to that, a building full of Cybermen is nothing.