People describe the feeling of depression as not being able to breathe but watching everyone around you breathing with ease.
The characters in Never Let Me Go suffer from their own profound endless depression. As children they could be equated to children in an orphanage. They might have aspirations in life, but they also know that they have to live within a certain parameter and will never achieve what they wish to. For orphans the children can want to reach a certain job but ultimately they know that as babies they weren't wanted, and because they have lived within an orphanage they have not reached enough schooling to accomplish something in the "real" world. For the characters they can aspire for a certain life but really they know that they won't achieve it because their life has be preordained and they will follow this life line until they die.
There is another major similarity between orphans and the characters. While children in underprivileged towns have a parent to fall back on, maybe only one, and maybe an awful example as a role model but they do have a parent who will love them and who they can turn to as they wish throughout their life. For both the characters and orphans when they reach a certain age they are dropped from the world they have known into the middle of the sea and are expected to learn to swim just as quickly as the children who have grown up in a pool their entire life. So maybe not the best metaphor, but if one group of people are accustomed to swimming within a real pool moving to the big ocean is a transition but not a life altering experiences. However, the kids who grew up in the kiddy-pool where they could stand are now dropped into the ocean and are expected to learn to swim, it is life altering and usually ends in disaster.
The characters in Never Let Me Go know they were modelled from the trash of society. If that is what their only alternative would be if they were not going to donate and die, what motivation is there to learn to swim.
We may not have clones in the real world, but we all know the feeling of drowning when everyone else can swim.
The science fiction in Never Let Me Go adds interest and a playful side to a story that reflects to the human experience.
