I think I'm doing a long run tomorrow. At this point in my training, long means 18 miles. And that distance makes me nervous. I am pretty sure I can do it, so why the nerves? Because it's tough and somewhat painful to do a long run. My experience is that all is pretty fine until the last 2 miles (which coincidentally are the "pushing new distance" part of the run). Although those 2 miles don't get significantly slower, they do get significantly harder.
Maybe nervousness just comes with the territory. I thought that having already run one marathon, it would be a lot easier to train for this one. In some respects it is easier, because there's reassurance in having done the distance before. The bottom line is this: training for a marathon is hard work. And the satisfaction that comes with finishing is directly related to the sacrifice it takes to train. So 18 miles tomorrow? YES!
(I'm still a little nervous)