Looking back at childhood play, the speaker remembers the "baubles" of the title: pointless, shiny things made from imagination alone. Adults dismissed them as ludicrous, lacking logic, form or function, and the speaker says the child's innocent mind still refuses to find that grown-up view funny. The first stanza is dense with rhyme and chiming sounds, which gives it a playful, almost sing-song energy.
The second stanza shifts. Children gallop on stallions across empty fields, or maybe sweet "candied" plains; even the speaker can't quite remember which, and that blurring is part of the point. Then comes the present: grown-ups wearing "protective masks and shields," waking from the "rush" of play as day breaks. The poem suggests adulthood means armor and defensiveness. The final mood is wistful and a little bitter. The speaker isn't just remembering fun but grieving the loss of a simpler way of understanding the world, one that seemed foolish to others but felt rich and real.