I was reading a very interesting profile of Obama from the January 2005 Columbia College Today, and came across this:

As for speculation that he could be the country's first black president, Obama says that he will not run for anything in 2008. He is quick to temper high expectations and scrying [sic] about his lofty political future with quips about how he doesn't yet know where the Senate bathrooms are, and how he'll be "sharpening pencils and scrubbing floors" for the first few years. "He says that the first thing is for him to learn to be a first-rate senator," says Jarrett, the finance committee chair. "If that leads to something else one day, fabulous. But first things first."

Politicians lie, or change their mind, about their ambitions every day, so I report this more for amusement than for the claim that it tells us anything about Obama.