Suddenly the Doctor thinks that maybe taking Rose on vacation like she'd asked wasn't the hottest idea.
Or perhaps it was. He winces at his mental double-entendre and shifts about in his chair, again. Though he knows that all the shifting in the universe won't cure what's ailing him now.
900 years, countless companions, endless deadly threats; but it's taken Rose and her tiny yellow bikini to make him lose his cool.
Maybe this is why he's always running for his life.
He's not sure which makes him feel more alive.
