A little boy finds a dandelion on his walk home in autumn and is instantly smitten. He picks it, treats it like a treasure, and shows it off to everyone, though he privately insists she belongs to him. The next day he rushes back from school to find her in a glass jar of water, and he is thrilled all over again.
Then the poem turns, and quickly. In its last two lines the flower fades, losing its yellow, and the boy simply forgets about her. There is no argument or sadness, just a flat, quiet ending.
The early mood is bright and playful, helped by the red and yellow leaves and words like "glee" and "ecstatic." Calling the dandelion "she" makes his feeling sound like a crush. The sudden drop at the end suggests how fleeting such enthusiasm can be, and perhaps how picking something beautiful to keep it often means losing what made it special.