The vivid details Bradbury uses occur at the end of the novel when Guy Montag has escaped capture by the Hound and society. His escape takes him swiftly through the town, anticipating capture at any minute, with the Hound closeby. Within feet of the river, the authorities announce that everyone should open their doors to search for the fugitive (Montag). When the people all step outside, it is only then that Montag has reached the river and stepped in. His immersion erases the scent that the Hound has been following.
It is not just sheer relief or an adrenaline rush that brings the characteristics of the river so vividly to Montag. It is his immersion into nature and freedom that so overwhelm him, and he is like a newly born creature with his "meeting" of the water. The water is like "raw liquor" which he drinks in and even snorts up his nose. he cannot get enough of it. Montag travels—floating as in a dream—on the water, as the land passes him. He has left the horror of reality and moved into what seems unreal: peace and quiet that is a soothing balm to his soul.
The woods assail his senses as he begins to walk. He smells the scent of hay, hears animals and insects, and the rustle of trees: all away from the oppressive sounds and imprisonment of the city. And he recalls a time when he knew a girl who lived in this kind of place, who could put dandelions beneath one's chin and explain what she saw in the yellow reflection of the "flower."
And in the sky, he sees stars so multitudinous that they seem almost overpowering: he cannot remember seeing so many stars, so brilliant. The moon is also beautiful, casting its reflected light all around him.
In all of these things there is beauty, peace and a frightening sense of freedom. Here Montag becomes acquainted with the world as it truly is, not as it is "prepared" for him, or explained to him. There is no one controlling what he sees or thinks or feels. Life until now has been precise and calculated. He and his neighbors have not experienced the world except as it has been "homogenized" by the government.
Bradbury provides these vivid details to convey the essence of Montag's rebirth into the world. The details flow over the reader as the images and sensations flow over Montag. All of these things delight Montag and give him release—and a sense of hope, though even that is not strong yet. The men he meets at the camp will help him grow stronger in the journey he now undertakes with his newfound freedom, and release.