He's getting sick of harvesting apples – there are so many of them, and he has to be careful not to let them fall. If an apple falls, it has to be chucked into the heap to use for making cider. Those cider apples are considered almost worthless.
He imagines that these thoughts about worthless apples and dropping things will haunt his sleep. He wonders if it will be a long, deep sleep, like the hibernation of a woodchuck, or whether it will just be a normal "human" sleep.