"The Patriot" starts right in the middle of a vivid memory. Before telling the reader anything else, the speaker of this dramatic monologue begins:
It was roses, roses, all the way,
With myrtle mixed in my path like mad:
The very first image of the poem is of a wild jumble of flowers and fragrant leaves carpeting the street where the speaker walks. The intense epizeuxis of "roses, roses" suggests that there were nothing but roses as far as the speaker could see.
This luxurious, overwhelming vision is like something from a dream. And so is the imagery of the next lines:
The house-roofs seemed to heave and sway,
The church-spires flamed, such flags they had,
The whole city where the speaker walks, in other words, seems practically to be dancing. It even seems to be on fire, metaphorically "flam[ing]" with bright "flags." Everything is energy, color, and movement.
The sounds of the lines add to their intensity. Note the alliteration (of /m/ and /f/ sounds), assonance (of /ah/ and /ee/ sounds), and sibilance of lines 2-4:
With myrtle mixed in my path like mad:
The house-roofs seemed to heave and sway,
The church-spires flamed, such flags they had,
By now, this imagery—in combination with the poem's title, "The Patriot"—might clue readers in that what the speaker is remembering here is a victory parade: his victory parade. He's the "Patriot" of the title, and he must have performed some heroic service to his country. Now, that country wildly celebrates him.
And there is something wild about these celebrations—and perhaps a little dangerous. Those heaving roofs, bright spires, and carpets of roses are certainly festive. But buildings that "heave and sway" might be on the verge of falling; spires that burn, burn down; and carpets of red roses might also make the streets seem to run with blood.
Even taken at face value, there's something not just joyful, but manic in all these festivities: roses running "all the way" through a city street is an awful lot of roses. There's a kind of crazed excess here, not just deeply-felt happiness or victory.
From the beginning, then, as the speaker remembers the day of his greatest triumph, there's a little foreshadowing here. The city might be wildly celebrating the speaker at the moment, but perhaps all is not well.
And the closing line of the stanza warns readers that something may well have changed since this parade. It was "a year ago on this very day" that the speaker made his procession over those roses, and these celebrations are only a memory now.