What is the importance of "light" in the poem, On Turning Ten?

Light is mentioned in three of the poem’s stanzas, each time with new meaning. In the first stanza, the speaker compares the effects of aging to “headaches … from reading in bad light” (Line 4) — suggesting a dim bedside light or nightlight. Later, they watch “the late afternoon light” (Line 18) pass “solemnly” across the garden (Line 19). Unlike the first light, this one is alive and in motion. Finally, light becomes a focal point in the last stanza: “there was nothing under my skin but light” (Line 29). Here it becomes a symbol of childhood magic and wonder.