Thomas Wolfe wrote a novel entitled You Can't Go Home Again in which he writes of his main character that he learned through hardship that you can't go home to someone who will ease your burden and save you:
For he had learned some of the things that every man must find out for himself, and he had found out about them as one has to find out--through error and through trial, through fantasy and illusion, through falsehood and his own foolishness, through being mistake and wrong and an idiot and egotistical and aspiring and hopeful and believing and confused....And, at the end of it [self-appraisal], he knew that....you can't go home again....back home to a young man's dream of glory,...back home to someone who can help you, save you, ease the burden....
Gene Forrester attempts to go "back home again" to Devon School in an effort to find the clue to his actions of the summer of 1942, back to Devon School to relive those terrible moments and gain some understanding of what he has done, to find that something that will "save him." Indeed, it is ironic that Gene walks through the portal of the First Academy Building that reads "Here Boys Come to be Made Men" in an effort to acquire an understanding of what happened to incite him to kill his best friend. On his second tour through the campus where he finds the infamous tree, Gene realizes that "it was what you had in your heart that counted." And, he knows that he can never go back again even though he can reencounter the tree that has "loomed in [his] memory as a huge lone spike dominating the riverbank." For,
Nothing endures, not a tree, not love, not even a death by violence.
Gene encounters the "fearful sites" of the campus that he is now able to identify and deal with as he perceives the selfishness of that summer so long ago as a somewhat detached narrator who arrives at self-knowledge.
Knowles does this for many reasons. Just to make it easier to absorb, digest, and assimilate, I will list the reasons.
Foreshadowing: Mentions the hard marble floor; describes the tree; establishes fear
creates a perserved "feeling" -- museum-like -- although touched up to look a little newer
Creates a tone by mentioning the weather, and later uses seasons to show a shift of tone
Time: Introduces that the school is a boys only boarding school during (which he attend during World War II)
wants to relive those terrible moments and gain some understanding of what he has done, to find that something that will "save him" as he returns to Devon to reflect on his past with a more mature prospective