The "Intimations of Immortality" Ode expresses and encapsulates the Romantic mindset—or at least, Wordsworth's own specific manifestation of it, which differs in some ways from that of his contemporaries and successors but was nevertheless highly influential upon them.
Wordsworth had stated in his preface to Lyrical Ballads that poetry should be written not in a special kind of language for verse but in essentially the language of prose, the ordinary everyday means by which people express themselves. Allowing for meter and rhyme and the occasional use of the archaic verb endings and pronouns traditionally used in verse (thou, thee, cometh, and such) Wordsworth writes in plain English. The Ode sounds like a man simply talking, expressing his feelings as if telling a friend about them. His absorption in, and identification with, nature is also a prime Romantic feature. The Romantic artist sees himself as one with the external world and is fascinated with its beauty and with the inner meaning it possesses for him. For Wordsworth, naturalness of language is a means of engaging with this natural, uncorrupted world, the "true" inner world as opposed to the exterior realm men have become concerned with in their artificiality.
This belief in an interior realm is pantheistic, identifying God with all of Nature. The Romantic artist sees himself as striving to reach or recover the godhead, and becoming one with it, if not already being part of it. In the "Ode," Wordsworth identifies a pre-existence, a primordial divine spirit from which we all have sprung:
Our birth is but a sleep and a forgetting,
The soul that rises in us, our life's star,
Hath elsewhere had its setting,
And cometh from afar.
In Wordsworth, the child is endowed with the ability to sense the godhead in nature, the "splendour in the grass" and "glory in the flower," but then with maturity loses that connection to the real, natural world, which is superior in the Romantic ethos to the world of men. For Wordsworth, the goal is to recover that sense, and thereby to reunite with God and with the truly beautiful.
This longing to recapture, or reunite with, a primal uncorrupted Nature is a seminal Romantic idea, and is expressed as well by poets whose variety of Romanticism in other ways differed from that of Wordsworth, such as Shelley and Keats, whose poetic diction did not partake of the simplicity and directness of Wordsworth's. At the close of "Adonais" Shelley sees himself mounting to the heavens, towards the soul of Adonais (by whom Shelley means the deceased Keats), which "like a star, beacons from the abode where the Eternal are." Keats himself, in his Odes, longs to connect with the scene of vanished nature painted on a Grecian urn, or with the nightingale dwelling in the forest where "there is no light / Save what from heaven is with the breezes blown / Through verdurous glooms and winding mossy ways." All of these poets of the next generation, despite their differences, were influenced by Wordsworth and the early stages of the Romantic movement in which a new set of ideas about man and his relationship to Nature and God were introduced.