Three lines, no title beyond a row of asterisks, and a whole change of heart packed inside them. The speaker announces a private decision: after a lifetime of something else, happiness is now allowed, and nobody, least of all "you," will stand in the way. The central idea is that happiness can be claimed by choice. It isn't something that arrives when circumstances improve or when someone grants permission.
The opening already suggests a story. "And for once in my life" begins with a lowercase conjunction, as if we have walked in halfway through a thought, or the end of a long argument the speaker has been having with themselves. "For once" is the quiet giveaway. It implies years of the opposite, a habit of putting happiness last or treating it as something other people were entitled to. The poem never describes that past. It lets the two small words stand in for it, and the reader fills in the rest.
The second line is the heart of the poem, and its verbs matter. The speaker doesn't say "I am happy" or "I will be happy." They say "I decided I deserve to be happy." Happiness here is a verdict reached after deliberation. "Deserve" is the most revealing word in the poem, because nobody needs to insist on deserving something they have never doubted. The word carries the ghost of the opposite belief, that the speaker once thought they did not. There is also a small grammatical surprise: "decided" is past tense, but "deserve" is present. The decision was made at one moment, but the entitlement it declares continues now, and presumably into the future.
The sound of the line backs this up. Listen to the long "i" repeating through "my life," "I decided I": the poem keeps saying "I," in vowel as well as in word. Then the hard "d" of "decided" and "deserve" gives the line a firm, stamping quality. Line three drops that long-i sound completely, and the speaker's grip loosens just as "you" takes over.
The form is plain and unrhymed, with no punctuation at all. The lines run six, eleven and nine syllables, so the middle line swells beyond its neighbours, which is where the speaker is making the main claim. It also ends on "happy," a soft, unstressed syllable that seems to exhale. The last line ends on the heavy, stressed "down." Without any rhyme to tie the lines together, that final word lands with a thud, and the poem ends on the very direction it is trying to refuse. Whether the effect is deliberate or not, it leaves the sense that the "weight" is still near enough to touch.
That last line also shifts the grammar of the poem. Until now it has been all "I." Only at the end does "you" appear, almost as an afterthought, and we never learn who it is. A former partner, a family member, a critical inner voice, or a past version of the speaker would all fit what is on the page, and the poem declines to choose. The phrase "aren't going to" is also telling. It's spoken, casual, a little defiant, more like something said out loud in a kitchen than a line of formal verse. And the sentence makes "you" the grammatical subject while giving the speaker the power: it is not "you can't" or "you shouldn't," but a flat statement of what will not be permitted. The image of weight, in "weigh me down," treats happiness as buoyancy, something light that can be dragged under by a burden.
What makes the poem worth reading is how little it does and how much that does. It isn't triumphant in the way a shouted slogan would be. The lack of punctuation and the ordinary diction give it the feel of a thought being said for the first time, possibly shakily, and that makes it more believable than a confident proclamation. Many readers will recognise the moment it describes, when someone stops waiting to be told they are allowed to feel good and simply says so. The poem captures that moment in three lines, and trusts the reader to supply the history behind it.