Mike Stone's poem is only a few lines long, but it holds a whole lifetime. A six-year-old and a sixty-year-old are placed side by side, and the surprise is that they ask the same question: how can something as big as a spirit fit inside a body?
For a child, the question probably comes from curiosity. Everything feels large and new, and the body seems a small container for all that energy and imagination. The poem suggests that at sixty the wonder hasn't gone away. The body has aged, and it may feel even more mismatched with the person inside, though the poem never says so outright. It simply repeats the thought: "He wonders the same thing."
The mood is quiet, gentle and a little amused. There's no complaint about getting old. Instead, the poem hints that the inner self stays curious and unchanged, even as the years pile up around it.