This is a poignant commentary on the years of life that have gone past now. As a boy grows older, he appears to be oblivious of his innocence. A quote from the poem:
but that is because you have forgotten
the perfect simplicity of being one
I'm not sure that Billy Collins has ever written the BIG POEM, the one (or two or three) that will place him up there with Robert Frost and T.S. Eliot and Sylvia Plath and Allen Ginsburg, and the like. However, Collins never publishes a bad poem - not once, to my knowledge. He writes poems that are polished, thoughtful, interesting, and at the same time accessible to the Common Reader. Hurrah for Collins!
This poem had me reminiscing about my 10th. It was 1975 and 'Jaws' had just come out. I had the coolest birthday ever - a pool party and everyone got rubber sharks as a party favor. I was afraid to get in the pool. I felt so ashamed to be 10 years old and afraid. 43 isn't much different.