Wounds don't really heal if they're being constantly reopened / irritated. Once the source of the injury is removed, some wounds will heal with time, and others require more specialized treatment. For that latter type, the lack of constant reinjury can feel a lot like healing, but it's not quite the same, and old injuries can flare up and/or have secondary issues down the line. Finding and healing them is a long and inconstant process that only really starts after escaping the cause of the damage. An analogy might be pulling someone out of a collapsed building, then treating them for the effects of asbestos exposure.