"Might have been and could have done, neither worth thinking on," reflects a sense of resignation and acceptance of past opportunities lost or missed. It suggests that dwelling on what could have been or should have been is unproductive, encouraging a focus on the present instead. This phrase emphasizes the importance of moving forward and not letting regret hinder progress.

In the context of Garth Nix’s "Goldenhand," such sentiments may resonate with characters facing difficult choices or past failures. It underlines a theme of letting go of regret and embracing the present, highlighting resilience and the importance of accepting life's uncertainties without being paralyzed by what might have been or could have been.