LESSONS CAN'T BE FORGOTTEN

"Once, l had a friend quite boasting.


Boasting or boastful?

Why not the present participle, BOASTING, as an adjective?

Are you saying that he was once engaged in boasting or are you noting that he is/was of the sort who tended  to boast or brag?  

1-First, you say: ...or are you saying that he IS of the sort... .How can you use IS after you have used: ...that he was once engaged in ... ? The incident and the person belong to the past, so you can't use IS.
2- Can't we use the present participle, BOASTING and the adjective BOASTFUL as both have very close meaning, which can be used in the context of their place in the poem? Don't ask me about the meaning l intend. Both of them can work where l used BOASTING.

One again you have not paid attention to what I actually said.

I wrote " that he is/was of the sort who tended  to boast or brag?  

And you have not answered the question that I asked you.

Are you speaking of an action that was undertaken at some point in time by your friend or are you indicating what type of character that he had?

1-Baldwin, you did not mention is/was. You mentioned only IS. Then you edited it.

Yes, I edited what I said,  but I did so before you made your comment.  
 
Now please answer my question (that I reformulated in my latest message above).

And BTW,  given the meaning of  the adverb "quite"  

: WHOLLY, COMPLETELY
not quite finished
2: to an extreme : POSITIVELY
quite sure
—often used as an intensifier with a
quite a swell guy
quite a beauty
3: to a considerable extent : RATHER
quite near
https://www.merriam-webster.com/dictionary/quite


 "quite boasting" is a solecism, but "quite boastful" is not.

No, l did not see IS/WAS when l wrote my comment. According to your question, take the meaning you like. Both BOASTFUL and BOASTING can work.

"Quite (wholly) boasting" raises the question "Completely boasting about what?".  
 
"Quite boastful"  raises no such questions.  
 
BTW,  there are lessons that CAN be forgotten, not to mention ARE often forgotten (hence the often made remark,  "I guess you didn't learn your lesson".)  For your title to  be relevant to what you claim in your text happened to you with respect to the incident you speak about,  it should have been "Lessons THAT can't be forgotten". or, more accurately, "A Lesson That I'll Never Forget".

Baldwin, you have to have some grammar lessons.
1- l will not ever forget. = l will never forget.
2- Quite: completely or very: and the degree depends on the pronunciation.
Don't tell the real poets to use your words if what they say is right. Moreover, don't correct if you are not sure. People's time is not yours, and they don't have much time to answer your provocative comments.

"Baldwin, you have to have some grammar lessons.
1- l will not ever forget. = l will never forget."

Who said otherwise?

"2- Quite: completely or very: and the degree depends on the pronunciation."

Is there more than one way to pronounce "quite"?

"Don't tell the real poets to use your words if what they say is right."

Leaving aside the question of whether what a "real poet" (presumably you)  says IS correct,  do you consider Mark Parsons to be one of the "real" poets here on DUP?

Yes, I have been there too. Great reminder, sir.Hugs and peace, O)

Dear O,
I am very glad you like it as it has reminded you of a similar situation. I am very happy to have such great reaction from you. Please call me Joseph.

I'm still waiting for you to answer this:

Leaving aside the question of whether what a "real poet" (presumably you)  says IS correct,  do you consider Mark Parsons to be one of the "real" poets here on DUP?

I prefer not to speak about other poets in our groups. I am so happy to criticize you and to get your criticism about my poetry.

"I prefer not to speak about other poets in our groups"

And yet you were perfectly happy to claim, however indirectly,  that I was not a "real poet".  

Moreover,  the reason for your excuse to not answer my question is clear:  had you said that Mark Parsons was indeed a real poet,  you'd then be obliged to eat your words about my being  talentless since he regards me as someone who writes well and evocatively .  

"I am so happy to ...  get your criticism about my poetry."

What a laugh given how you respond to it with ad hominems and red herrings and label my criticism of it as not worth taking into account.  What you really want , and, as is plain,  the only thing you are willing to accept, is  praise.

Have you forgotten what you have written, and was everything you said about my poetry true?

"... was everything you said about my poetry true?".  
 
Using your stated criteria for what must be the case --i.e.,  your reading of what is and is not good poetry -- as my guide in assessing things,  yes, what I said about your poetry is true.  
 
And is there more than one way to pronounce "quite"?

Like the specific event narrated:  changing your answers on the exam.
Like the description of the friend as a blow-hard.
This reader reaches the end of the poem and wonder why this lesson was unforgettable to the speaker--
Were it mine, I'd focus on bringing out the specifics of the event, and work towards understanding how and why this event toughed me so, remains so memorable.
Enjoyed!

Very dear Mark,
Thank you very much for liking several points in my poem and for enjoying it. It is very kind of you. I hope this  poem will be the beginning of a strong friendship between you and me.
This lesson is unforgettable to me because l changed my correct answers and wrote his wrong ones because of his false pride of himself and bragging. Consequently you can guess the mark l had, and what l would have deserved if l had kept my answers. This is quiet clear in the poem. Thank you very much for your kindness and interest. Please, keep in touch.

Perhaps I've read Mark's comments incorrectly,  but what I see him saying is that your submission did not accomplish all that much since you left out what was essential for you to have said what you now tell us you wanted to say.  
 
I note too that your response to Mark indicates that he is someone who knows what a good poem looks like and what it has to have within it to fulfill a basic aim of poetry -- to create something that a reader can experience and enter into.  
 
If this is the case,  what then do you make of his positive responses to my submissions?  Do they show a sudden loss of the critical acumen you take him as showing towards this piece of yours?

Perhaps

I took a test
while sitting next to my “smart” friend,
a test I had not studied for.
And so I stole my answers surreptitiously
from the page that he was writing on,
thinking they were full embodied in
his proclamations of
his mastery of subjects taught
within the university.

But to my consternation in the end
I found that he was not the brilliant kid
I thought he was
or let alone, the one
he’d  bragged himself to be
because I saw
that when my graded test
was handed back to me
I’d barely “earned” a D.

What lesson did I learn from this experience?
That I should always study more
and have more sense
to never be so dumb to trust
a boy who boasts how intellectually
equipped  he is
when bragging shows he probably
is compensating for his knowledge that
he’s really not a wiz.