Thanks for sharing, Michael, the poem is both inspiring and thought-provoking. It's an old story: "Words do not mean, people mean", which is always striking, nevertheless, any time we had such experience ourselves.
Replying to the thread Words are Windows, or They're Walls:
You ask how we can apply this to a classroom. I would say: in lots of ways; depends on LL's level, age (understood as experience rather than being ...-year-old), and educational background; our courses and teaching aims too.
If, for instance, I brought the poem to some university students as a lecturer in Psychology, or Interpersonal Communication, while delivering such subjects in English, I would read the poem to illustrate how, expressing our thoughts/ feelings, we can be either understood or misunderstood (same words often meaning different things to different people: e.g. what seems to be rude/ ill-mannered to one, is neutral, or even nice to another, etc.). A good opportunity to discuss our linguistic codes as well: more or less elaborate, with more verbs or adjectives, …, - depending on our social surrounding, education, gender, culture, and whatnot).
If we do such courses as Linguistics and Intercultural Communication, we might use the poem to stress the importance of nonverbal aspects of speaking, which we sometimes underestimate (smiling/ frowning, intonation, … whether some words accompanied by these non-verbals could be/ intended as a threat/ joke/ warning, etc.). Lots of implications in terms of different cultures: even sharing the same feelings [see the end of the poem], we can express them very differently, as our cultures give us their 'proper' means (not to) say/ (not to) show something.
In a language/ communication skills training class, I would start with reading the poem (its fragments) to give my students, then, a work-in-group task: one of them to say something (e.g. "you want to leave for a while/ see someone no longer"/ ...), others to make comments on how they understood the message (as a threat/ joke/ warning/ …), and why. The more comments the better, to catch possible nuances in understanding what others mean. Taking turns is also essential, to give everyone the opportunity to express same ideas in different ways - and, last but not least, to have feedback!
So, to come back to your question, Michael, how to apply the poem to our classrooms, there are lots of ways indeed. Hope this might help too.
Lala Sadykhova, PhD