Discussion: I'd guess you would be sore...

I'd guess you would be sorer if you had run more in the second half. And I'm sure you would have run more in the second half (and been quite a lot faster overall) if you had gone slower in the first half.

But maybe that is impossible for you.

I'm quite sure you're correct on all counts. But I went in with the thought that I'd shoot for 4 hours (new territory for me) and try to do it as evenly as possible (which obviously failed).

Time to start slowing down my long runs until I can find that magic spot where I'm not walking, but can maintain for a long time. And hopefully that's a spot that also allows me to absorb what I'm taking in rather than accumulating stuff until it blows...

Well, I still think you've got it wrong. I'd suggest that you want to learn to be smart enough to walk from time to time (like uphills) well before you need to. Certainly starting in the first hour. You don't lose much time, you digest stuff better, and you last a lot longer.

The only impediment is the normal male ego.

Good point - when I try to slow down too much, my gait feels forced - perhaps a combination of walking and then running at a comfortable, but not excessive pace might work. I should be able to do that as long as I do it when I'm not running with other male egos...