The speaker looks back at a time when playing was easy and natural, and admits that something has changed. They still say "hi," but the very next word is "bye," as if every connection ends almost before it starts. The short, plain lines make it feel like a child or teenager trying to describe a feeling they don't have words for yet.
The middle of the poem is full of contradictions. The speaker loves to play but also loves to sleep, doesn't understand but also does, understands why people are mean but doesn't. The most telling line may be "I say I understand / But I dont." It suggests someone pretending to cope, nodding along while feeling confused or hurt underneath.
The repeated opening stanza makes the poem feel stuck in a loop. The only new line, "I don't know why," lands quietly and honestly. The mood is tired, withdrawn and a little sad, though never dramatic.