How does the Devon school seem different now,15 years later,compared to when the narrator attended school there?

He notices how much like a museum the school looks, how lifeless and polished; but the place brings back even keener memories for this preserved quality of appearance. It is a rainy, cold November day as he inspects the school grounds, and revisits the cold, hard marble stairs in the First Academy Building, which seem to hold some kind of memory for Gene; he also trudges over the muddy playing fields, to the river, and a tree that he and Phineas used to jump off of, bravely. He notices, when he sees the tree, how vast the difference is between youthful memory and adult perception.