An apology usually looks backward, but "mistakes" ends by looking ahead. It begins with the plainest confession possible, "I am so very sorry / this was not meant to happen", and finishes with a plea to someone else: be careful. The only thing we have about the writer is the name cloudsonthemoon, so the best way into the poem is through its words. They show a speaker who is grieving and taking the blame, and who is also trying to turn the loss into a lesson.
The poem never says what the "wonderful creation" is. It could be a friendship, a romance or something else shared between two people, and that vagueness lets many readers see their own broken relationship in it. The speaker also never names the mistake. We get its consequences, not its cause. That fits the subject, because regret often circles the damage without being able to look straight at the act.
The form helps. There is no rhyme and no steady meter, just short lines in stanzas of one or two, with a lot of white space. The line "something that has been building up over years" is stretched out, as if the years were piling up inside it. The next stanza, "is destroyed completely / never to be rebuilt", is short and heavy. The line break after "completely" gives the loss a moment to land before "never to be rebuilt" closes it off. The speaker's language is casual ("it's crazy how quickly things can happen") and borrows a stock phrase, "in the blink of an eye." These sound like words someone grabs when they are too shaken to find better ones, and that makes the sorrow feel unpolished and believable.
The central image is the castle, and its meaning shifts as the poem goes on. At first it is the shared relationship, and the speaker imagines its end gently: "the ivy leaves will grow up the walls", "the old stone will turn to ruin / and overgrown plants." The future tense matters here. The destruction itself was sudden, but the aftermath is slow and almost peaceful, with nature gradually covering what was lost. Ruins can be moving to look at, and the poem seems to know it. Then comes a surprising turn: "you and I will be new separate castles / each far away." The castle is no longer the thing between the two people. Each person becomes one. "New" suggests growth, while "far away" and the stone walls suggest isolation. The poem offers survival and loneliness in the same breath.
The most revealing line may be "but I will never forget the mistakes / I made in it." The speaker says "I", not "we", and takes all the responsibility. The word "in" is telling too, since the mistakes are placed inside the castle and will stay there as it crumbles. The title, in lowercase and set in guillemets, quietly makes the same point by being plural. There was no single catastrophe, only a series of errors.
Then the address changes. "So I beg of you" is more formal and old-fashioned than anything before it, as if the castle story has pulled the speaker's voice toward fairy-tale language. The advice is nearly a whisper: "be careful with your actions." In the last stanza, "on wrong word" is almost certainly a slip for "one wrong word." One wrong word "or sudden movement / can kill everything beautiful." Here the poem swaps stone for something alive. The word "kill" is the harshest in the poem, and "sudden movement" suggests approaching something shy and easily frightened. The relationship was solid enough to be a castle, yet it died like a living thing. The ending also echoes the "blink of an eye" from earlier, so the poem closes on the same fear of how fast things change.
The poem's significance lies in its honesty and its restraint. It does not ask for forgiveness or blame the other person. It offers regret, a small hope for two separate futures, and a warning from someone who learned too late. A reader may wonder who "you" really is: the person who was lost, or anyone who might one day hold something fragile. That uncertainty keeps the poem open, and it turns a private apology into advice that reaches beyond the one relationship.