Last long run before the Stockholm Marathon

Today I ran what was probably the longest distance I've ever run. I ran twice around Brunsviken and then made a lap around Ulriksdals Slott. I estimate that the total distance was 26-28 km. I only stopped to walk a few times, and just for a minute or two each time. It took 2:45 to complete the run, and I'm absolutely exhaused. Today's run gave me more confidence that I'll be able to finish the marathon, in part because of two surprising sensations that I experienced for the first time during the run today:

1. Several times during the run, starting some time during the second lap around Brunnsviken, I began to feel like I was on autopilot. I didn't have to think anymore; I just ran. It was a surprising sensation, but it was welcome because it made the running just flow, as if running were the natural state for my body to be in. I've read about people getting in the zone when doing extended physical or mental exertion, especially if this involves repeating a task that has been done many times before. The task suddenly takes much less mental effort. It just happens. The sensation lasted only for perhaps ten to fifteen minutes at at time, and it went away if I became distracted by uneven terrain or a grumbling stomach; but it often came back a few minutes later.
2. Around km 15, my hips and knees began to complain in earnest. It became hard to ignore the pain that increasingly accompanied every step. I allowed myself the luxury of a minute's walk, but each time I did this I set a deadline: After one minute, I'll start running again; or When I get to that lamp post up ahead, I'll get moving again. By setting a definite limit on the rest time, I think I managed to keep my body warmed up and in running mode. Walking for longer than a couple of minutes might have led my body to begin the to switch to let's go home and have a beer mode. My system seemed to work, and I kept myself to the bargain each time. This meant that I resumed running even though my joints were still hurting with each step. It was hard, but I kept going. Some time well after km 20, a surprising thing happened: the pain began to subside. It happend rather suddenly, and the running became much easier at that point. My hips and knees were almost numb. No, this isn't quite right. They weren't exactly numb, but the pain was dull, and significantly diminished in magnitude. Thanks to this I was able to keep my speed up during the last few kilometers as I ran out to Ulriksdals Slott and looped around Bergshamra Centrum before heading home.

I think I've come to the threshold between typical everyday exercise running, and real endurance running. The two surprising sensations today were really welcome, and I hope they will bless me with their presence on 4 June. The last 10-15 km of the marathon is definitely going to be the most difficult.

In the coming week, I plan to run twice or three times, and for no longer than 10 km each time. The week before the marathon, I will only jog a few km at a time, and probably only in the first half of the week. Diet and rest will be as important to success as training.