This poem is a bit odd in that the speaker of the poem is Walt Whitman. Section 24 has Whitman name dropping himself, so the speaker is Whitman or the persona that Whitman is creating for himself in this poem. Readers can learn a lot about the speaker from this poem. The speaker is clearly someone that is happy with himself and with life in general. It's why he celebrates himself; however, section 24 also lets readers know that the speaker isn't trying to present himself as anything better than a normal, everyday kind of guy that does normal stuff and loves being a part of all of that.
Walt Whitman, an American, one of the roughs, a kosmos,
Disorderly fleshy and sensual . . . . eating drinking and breeding,
No sentimentalist . . . . no stander above men and women or apart from them . . . . no more modest than immodest.
Notice the talk of common pleasures like eating, drinking, and sex. The speaker is presenting common man pleasures, and this gives him a very common man or populist persona. Personally, I really appreciate the above lines because there are times when I really don't like the speaker. He just seems too happy with an over inflated sense of self, but this part lets me know that he still considers himself just a regular guy.