Hills, surface, everything - it's all really, really tough. I was flat on my backside at one point after tripping on a lot of loose shale - it would have been at around 16 miles, on the bit above the lake before the river crossing. But at that point a cut hand was really the least of my worries.
The slideshow makes the course seem much flatter and easier underfoot than it really is. Hence why I got my time estimation out by more than an hour!
I completely echo what Costanza says about the last three miles, too. I remember narrow paths and stumbling over tree roots in complete dizziness, barely able to stay upright. By that point too, the super-fit runners who'd started two hours later than me were passing me, and I was trying to keep moving and get out of their way. What really touched me was how supportive they were, though. I'd have thought they'd be annoyed to find people like me in their way, slowing them down, but no - the fastest runners, with no more fat on them than a greyhound, were telling me "well done" as they passed and even giving me jelly babies. That's what I meant about the camaraderie earlier - the runners were absolutely lovely.
Would I do it again? Yes, one day - though this year I'm doing a flat marathon instead! I remember crossing the finish line, being handed my medal, and telling the woman who gave it to me that the Lakeland Trails Marathon was the "hardest thing I'd ever done." I still stand by that. But it was also one of the greatest days of my life.