A sudden insane urge to stop came to him. Just to see if they really meant business. He rejected the thought indignantly and a little fearfully.
Prior to this the walkers discussed how one of the previous contenders got his "ticket" right at the start because his legs froze. From this statement we can conclude how lightheartedly and jokingly the walkers take this whole thing at the beginning. Garraty as well doesn't really believe that the "ticket" means actual death and feels tempted to test it.
One boy had been screaming. That was his most vivid memory. Every time he put his foot down he had screamed: I can't. I CAN'T. I can't. I CAN'T. But he went on walking.
Garraty describes the one time he went to see the walk when he was younger. This has a foreshadowing quality in it as we can see later in this walk towards the end when a boy named Klingerman starts repeating this exact same thing while walking.
"I understand what it is to die, I think," Pearson said abruptly. "Now I do, anyway. Not death itself, I still can't comprehend that. But dying. If I stop walking, I'll come to an end. "
One of the many discussions about death, the walk, the road begins to represent life to the walkers, even while discussing the prize they do it with an ironic undertone as something distant and unreachable. There is only the road, the walk and the Grimm reapers holding guns at the side of the road waiting for them to stop to collect their bodies and souls. Even at the end of the walk, when Garraty is the last one walking, he is unable to stop because stopping equates to dying.
