Memory is the subject here, and the way the past refuses to stay in the past. The speaker is haunted by "deeds done past," which suggests they did something they now regret, though the poem never says what. We only get the aftermath: scars. Those marks should mean the damage is over and healed.
The last two lines undo that comfort. Seeing their own blood, even in memory, feels as vivid as if the wounds "still wept." The word "wept" is a striking choice, because it makes the injuries sound almost like they're grieving, and it hints that the pain is emotional as much as physical.
The mood is quiet, heavy, and unsettled. The short, plain lines feel like someone confessing rather than performing. The title, "Flashback," fits neatly: the speaker isn't just remembering, they are briefly pulled back into the moment, and the poem leaves us with the sense that healing on the surface doesn't mean the memory has let go.