What Are Your Favorite Poems?

This being National Poetry Month, I'm wondering what your favorite poems are.  Last night I read with a friend at the Little Boston Library, and we shared some favorite poems.  I read Robbie Burns' "To A Mouse," and Jenifer read Hayden Carruth's poem "The Cows at Night."  And today in my Pilates class I was talking about the library reading and many of the people in my class began reciting poems they remembered as kids in school.  It was great fun.

So, my questions are:

What poems did you learn by heart, and what poems remain favorites of yours?  I'd love to hear what you hold dear.  If you comment, and are able to, please post a link to the poem so that other readers might enjoy them, too. 

I have many faves, and over time I'll add them here. Here's one for starters:

Forgetfulness
--Billy Collins

The name of the author is the first to go
followed obediently by the title, the plot,
the heartbreaking conclusion, the entire novel
which suddenly becomes one you have never read,
never even heard of,

as if, one by one, the memories you used to harbor
decided to retire to the southern hemisphere of the brain,
to a little fishing village where there are no phones.

Long ago you kissed the names of the nine Muses goodbye
and watched the quadratic equation pack its bag,
and even now as you memorize the order of the planets,

something else is slipping away, a state flower perhaps,
the address of an uncle, the capital of Paraguay.

Whatever it is you are struggling to remember,
it is not poised on the tip of your tongue,
not even lurking in some obscure corner of your spleen.

It has floated away down a dark mythological river
whose name begins with an L as far as you can recall,
well on your own way to oblivion where you will join those
who have even forgotten how to swim and how to ride a bicycle.

No wonder you rise in the middle of the night
to look up the date of a famous battle in a book on war.
No wonder the moon in the window seems to have drifted
out of a love poem that you used to know by heart. 


*  *  *

What do you know by heart?