Iuvseokjin's "Gone" starts from a familiar saying: people don't realize what they have until it's gone. Then it turns the saying around. What about those who did realize, who treasured what they had and never took it for granted? The speaker is asking about a quieter, less talked-about kind of grief.
The poem's central idea is that appreciation doesn't protect you. These people tried their hardest to hold on, yet could only watch helplessly as the thing they loved most slipped away. The word "damn" makes the tone feel raw and a little defensive, as though the speaker is pushing back against an unfair assumption that loss is always the fault of carelessness.
The final line, a question in quotation marks, suggests the speaker thinks this is worse, since there is no regret to blame and no lesson to learn. The mood is aching, helpless, and quietly angry. The poem doesn't offer comfort, only the sense of being understood.