My mother's never seen this little poem by Dana Gioia, but I'm a fool to have never shared it with her:
So much of what we live goes on inside—
The diaries of grief, the tongue-tied aches
Of unacknowledged love are no less real
For having passed unsaid. What we conceal
Is always more than what we dare confide.
Think of the letters that we write our dead.
There's nothing new in the what of the poem, and no surface difficulty at all. It appears to be a plain statement of a too-common situation, and still the last line is like a hammer.
Some of its impact is metrical: the first five lines are completely regular iambic pentameter; after the strong stop at the end of the first line, lines two to four are enjambed, with two strong caesuras, almost hiding the line endings; line five once again stops cold; the last line opens with the only metrical substitution of the poem, a trochaic first foot that quickens the poem's pace before that last stop. The middle lines are metrically tied together in a bundle of small examples of the first line's thesis, while the last line's final example sums and shows the extremity of all that went before.
But it's the rhyme which is really masterful. It appears, at first, to be aXbbaX, with "aches" and "dead" unrhymed — which would be, on it's own, perhaps merely clever. But look closer at the apparently unrhymed lines. Very near the end of each is an a rhyme, the perfect rhyme "tied" in an unaccented position and the near-rhyme "write" accented. "aches" is faintly echoed in "unacknowledged," apparently finished in the unvoiced "s" of "less," and revived by the long "a" of "dare" in the penultimate position the poem has taught us matters to it. And "dead," of course, rhymes with "unsaid" at the strong caesura of line 4, and the poem clicks closed like the trap which it reveals so many of us build for ourselves.
And still it never preaches, never accuses, never enjoins us to anything but awareness.