I'd studied 16th century science and magic. I thought it was strange that people were interested in the same kinds of things my research was about. The more I thought about it, the more intriguing it became and pretty soon I was writing a novel about a reluctant witch and a 1500-year-old vampire.
One funny thing is, though, I wear my watch on my right hand and I'm actually right-handed. People always wonder why - I don't know myself, I've just always done it that way and I like it the way a good watch fits on my right wrist.