What is a poem, exactly?

It all started when Amitava Kumar posted a poem on his blog. Called ?Man Writes Poem? by Jay Leeming, from Dynamite on a China Plate. ? The Backwaters Press.

Reading the poem made me start thinking, what exactly is a poem?
I started answering the question in Space Bar?s comment section. So the first paragraph of this poem was my comment in Space Bar’s blog. But the more I thought about it, the more my poem grew… and I ended up with this:

————
I am more and more confused these days
Not that I wasn’t confused before, just
that I am a little more lost and bewildered
I ask myself, and I ask passersby
the same question every time
No one responds, perhaps no one knows -
What exactly is a poem these days?

How does one write a poem?
Do you start off with eloquent lines
About the red earth and purple coneflowers
Swollen rivers and windy nights
Throw in some flying Chihuahuas
For that magical, dreamlike touch?

Or perhaps you write about emotions
Melancholy sounds a good word to use
Also grief, joy and passion.
Soon your poem will start to take form
The lines on the page even taking on new shapes
Like a saw-toothed blade, or a picket fence
That has fallen down.

But where is the rhyme, you ask
Here is no pentameter, this is just
Broken Prose, where is the rhythm?
But you see, we are not in the dark ages
When poetry was corseted in rhyming words
And metered lines.? We are modern.

Our thoughts are new, our words are new
Spelt differently, compressed,
vowels excised, numbers added
Thumbed rapidly into concise messages
Who has time for verse?
Our music is fast-paced, our life is a race
Our poems stutter to keep pace.

The dictionaries, you insist, define a poem as
Metrical writing. Perhaps the dictionaries
Need updating.
We update our Facebook pages
every fifteen minutes.
A new word forms every minute, yet
Why do we update our dictionaries only
once in several years?

Perhaps you may want to take
A course in Poetry Appreciation, 3 credits
And four thousand dollars.
Or buy the bestselling book,
?Poetry for Dummies?, that may (or may not)
Help you identify poetry.

So what is a poem, then?
I hate to break this to you, but you will find
If it is shorter than a novel, in most cases
(Though there are some that are really long.)
If the lines are short, even if the words are long
It must be a poem, but trust me
The real rule with a poem is
You will know it when you see it.

Sometimes, though, you may find
A beautiful poem, but the author
may have really intended to write prose
In which case you can always say
“The author?s lines are very poetic.”
For really, who knows what a poem is?