Mark McGwire

What cracks me up is people who think I don't take baseball seriously. It's the most important thing in my life. They don't know how hard it is for me to get a bad game out of my mind. I still can't, but I'm getting better.

The historical novelist has to consider what has actually happened, while the SF writer is dealing in possibilities, but they are both in the business of imagining a world unlike our own and yet connected to it.