Rachel Habraken's poem is about the moment you realize childhood is over. The speaker doesn't describe it as one big event. Instead, small things slip away: butterflies drift out of reach, swings no longer feel like flying, and memories start to fade. When all of that happens together, the speaker says, we can be sure we are "no longer children."
The feeling here is wistful and a little sad. Being happy is no longer enough, and the mind gets pulled between what is real and what is imagined. Dreams become "lesser thought," and the line about the stars being out of reach sounds like a quiet disappointment, not a dramatic loss. Words like "tarnished," "stained" and "wasted" make the early days sound spoiled, as if growing up leaves marks on them.
The poem ends with the end of summer, a gentle image for something warm and bright slowly fading. The mood is nostalgic and resigned, more a sigh than a cry.