Predating the Beatles

Whitman makes his case boldly and enthusiastically in the first three lines of Song of Myself

I celebrate myself, and sing myself,
And what I assume you shall assume,
For every atom belonging to me as good belongs to you.

As familiar as these lines are, it took a discussion at edX

Often what we talk about, in any piece of literature,
is struggle-- either struggle with oneself
or even Emerson and Thoreau, who talk about the fact
that we're all connected through some divine dust.
They're still talking about the fact that the individual
is at odds with society and the government.
And even with, perhaps, European culture or farther back than that.
And so the opening of this poem is so unique and strange in that
it says there is no struggle here.
I am you.
And you are me.
And we celebrate ourselves.
And let's go forward with that.

to help me realize the similarity in thought in I am the Walrus.

I am he as you are he as you are me
And we are all together