"I never, never, never thought I would still be out here, but I have nothing else to do. I'm pretty good at tennis still, so why not? I'd just rather I didn't sit at home all day."
Williams celebrated her recapture of the world number one ranking with her best performance of the year in a 6-3, 6-2 trouncing of Maria Sharapova to reach the Qatar Open final on Saturday.
On Sunday, she will face defending champion Victoria Azarenka, the outgoing world number one, for the title.