[1] The day after he wrote "My Heart Leaps Up", Wordsworth began to write his more ambitious "Ode: Intimations of Immortality".
Some commentators have speculated that Wordsworth felt such joy because the rainbow indicates the constancy of his connection to nature; he was 32 years of age when he wrote the poem.
[3] In other words, Bloom suggests that Wordsworth's poetic gift relied on his ability to recall the memories of his joy as a child.
[5] Because a rainbow is shaped like an arc of a circle, Fred Blick speculates that the word ‘piety’ at the end of the last line is a deliberate geometrical pun, signaled by the phrase ‘bound each to each’.
[6] "The child is the father of the man" is the title of a chapter in Machado de Assis's 1881 novel The Posthumous Memoirs of Brás Cubas.