The poem moves like a dream, and it begins as one: the speaker, asleep, drops through a hole beneath the pulpit. The pulpit suggests church, sermons, and received authority, so the fall feels like slipping out from under official teaching. What the speaker lands in is a tree, which "they" mistook for a book of great art. That small twist carries the poem's quiet argument. Some people look at a living thing and see only a cultural object to be read and admired.
The last stanza turns plainer and more personal. The speaker admits being unable to "under-/stand or study / alone indoors." The word "understanding" is split across the line break, as if it is being pulled apart to reveal "standing" beneath it. The poem seems to say that real knowing needs the body, the outdoors, and perhaps company, not a closed room. The mood is dreamy and gently playful, with a note of restlessness and a longing to leave books and buildings behind.