"Some people could look at a mud-puddle and see an ocean with ships. But Nanny belongs to that other kind that loved to deal in scraps. Here Nanny had taken that biggest thing God ever made, the horizon--for no matter how far a person can go the horizon is still way beyond you--and pinched it in to such a little bit of a thing that she could tie about her granddaughter's neck tight enough to choke her." What does this mean?