"Yeah. I know." He means it to be reassuring, but it doesn't end up sounding that way. He gets the feeling that Jimmy feels the same as he does sometimes: that neither of them were really supposed to be there. He returns his gaze to the waves breaking on the shore, trying to think of something that might help, but nothing comes to mind. Any reassurance he tried to give Jimmy now would be a lie, and he felt he'd probably be lying to himself, too.