Opening on a rush of growth, the speaker says "We blossomed too fast," and the word "too" already tells us this isn't simple celebration. Something bloomed early, before it could last. The next lines shrink time down: the hours were "only short," and they "have since passed." There is a flat, resigned tone here, as if the speaker has stopped arguing with the loss and is just reporting it.
The final line repeats the first with one change. Blossoming becomes decline, and the speed stays the same. That echo makes the poem feel like a closed circle: rising and falling were equally quick, with no long middle to enjoy. The title suggests the "kids" were dramatic, perhaps intense about everything, and the poem's brevity quietly contrasts with that. Where they were loud, the speaker is spare. The mood is wistful and a little bleak, with a sense of looking back at youth, or a shared moment, that burned bright and ended abruptly. The poem doesn't say what exactly was lost, which leaves the feeling open.