I read Atlas Shrugged when I was 18. The world in the book exists in a vacuum, and it's easy for an impressionalbe teen (or adult-- look at Greenspan) to get drawn into that way of thinking. It's been awhile, but her philosophy of rational selfishness wherein "all principal virtues and vices are applications of the role of reason as man's basic tool of survival (or a failure to apply it): rationality, honesty, justice, independence, integrity, productiveness, and pride." The idea that your value in society should be a sole reflection of the value you add to society, pure meritocracy. There was something oddly invigorating about that outlook, and it was impossible not to read it without aspiring to be like her larger-than-life characters, and wanting to apply that philosophy in looking at personal, domestic, and international problems.

However, the more I used this logic in examining problems, the more disturbed I felt. Sure, a meritocracy sounds great, but how meritocratic is it when you consider that even in her own book, the majority of the protagonist are born into extremely wealthy/aristocratic families. That they are presented with opportunities that ease their path to success, opportunities that the average and poor do not have access to. That the poor, are looked down on and considered "leeches", and any movement to increase opportunities for the lower class would be "allowing poor people to 'leech' the hard-earned wealth of the rich". Unless you are producing some new good or technology, unless you are adding noticable value to society, then you are nothing, you are worthless.

The worst was when I applied this logic to my personal problems. An 18 year old kid forced to live in isolation, diagnosed with a rare and costly illness (which I would eventually recover from!), and being treated at a government sponsered hospital. My value to society was 0, and according to the logic of Ayn Rand, I was a leech to society, I deserved nothing, with death being the inevitable outcome. I disagreed. I have value, you have value, we have value, life has value.

Not sure how well the above applies to your question, but I hope it does.

P.S. I'm also a big fan of Terry Pratchett, so I'm adding "The Long Earth" series to my list!