Images in words

In the poetry class I'm taking, we don't talk very much about form.  All are older people, many of whom always had a longing to write poetry but did not -- or possibly wrote a little but hid it away or threw it out when cleaning. Now they come to class with poems of many sorts on many subjects, often predictable subjects (grandchildren, nature, memories)  Some are good, some so-so, but they are writing and it feels good.  I've been a serious reader and considerer of poetry most of my life, only occasionally writing something that I put in what looks like poetic form but which I rarely consider "real" poetry.  I especially appreciate approachable poems, like those of Ted Kooser, Billy Collins, Mary Oliver although I ponder more on "harder" poets.  The poem I want to share today is one in which Ted Kooser writes very understandably about a student but underlines his vision with a metaphor which is never stated. 

               Student

The green shell of his backpack makes him lean
into wave after wave or responsibility
and he swings his stiff arms and cupped hands

paddling ahead. He has extended his neck
to its full length, and his chin, hard as a beak
breaks the cold surf.  He's got his baseballl cap on

backward   as up he crawls, out of the froth
of a hangover and onto the sand of the future,
and lumbers, heavy with hope, into the library.