Radiolab "Words"

I was really intrigued by the case of the 27 year-old man who had never learned language.  A while back I watched a documentary about feral children.  The documentary stated that because these children had never learned language and were past the age of 4, they were now incapable of learning it.  The neurologist on the documentary showed that the part of the brain that processes language was malformed.  So when I listen to this podcast I was very absorbed by the fact that this man was capable of learning language.  The difference in the two cases must be that he was around other humans, and the language center of the brain formed in a very rudimentary state based around human non-verbal communication.  The part about the reaction of the 27 year old after realizing his first word and making the connection between language and object was really beautiful; about seeing a whole world open up in his eyes. 
The case of the woman who had a stroke and went in and out of understanding language was interesting in the way that she had to re-teach herself language.  I thought the part about her feelings of bliss when she wasn’t thinking in verbal thought was kind of misplaced.  Animals don't think in verbal, language-based thoughts but they are definitely not at peace or in a state of bliss constantly.  The feeling of bliss that she experienced probably had something to do with the pleasure center and other areas of her brain being affected by the stroke. 
The currently evolving new language segment was strange in relation to the 27 year-old's case.  Why had the one group of deaf children, with no language being taught to them, develop their own means of communication and eventually sign language, and the other group with the 27 year-old hadn't?  Is the development of language dependent on population size?  It was really impressive that after only one generation of basic language skills, the second generation was able to start expressing, and thus thinking about, abstract thought and concepts.  It also make me wonder if abstract thought is only capable when language is present, and language presents many restrictions in abstract thought (like the issues around I, or in the metaphors we live by), then isn't that sort of a strange catch 22, or a paradoxical relationship with language and abstract thought?