What is the significance of Montag's being "fully aware of his entire body"

This quote is found near the end of the book, as Montag and the other survivors experience the contrasts of the wilderness. Montag reflects on how Mildred would not have been able to tolerate the lack of stimulation, but that Montag, by contrast, is now "waking up" to the sensations of his own body.

This is a reference to some of what Faber spoke about when he and Montag discussed the elements necessary for their society to recover from its self-induced stupor. One element was the ability to reflect on what had been learned - but this was impossible, according to Faber, because there was no room for reflection when one's senses were filled up and overloaded with programming at every moment and every place. We see this when Montag is attempting to memorize the passage from his book and "arguing" with the Denham's ad on the subway.

In the wilderness, the complete lack of traditional stimulation is, ironically, stimulating. Montag's "face, his mouth, his eyes stuffed with blackness", and "the more he breathed the land in, the more he was filled up with all the
details of the land." The entire experience is wholly novel for him. This is probably the first time that Montag has had to actually rely on his body and "listen" to it in this way, and also the first time that he has experienced nature in a way that allows it to compete with the programmed reality of society.