"That samurai was right who refused to compromise his character by a slight humiliation in his youth; 'because,' he said, 'dishonour is like a scar on a tree, which time, instead of effacing, only helps to enlarge.'"
Ah yes, once again the words of Inazo Nitobe's Bushido.
This paragraph deserves some thought. Although the original context is discussing the role of shame, and how this emotion is the basis of all moral behaviour and honour, the scarred tree analogy goes so much further. We all have such wounds that have increased over time rather than diminished. Some are based in matters of confidence; some are in areas of relationships; and some are based in more tangible and physical injuries that we ignored until they spiralled out of control.
Technically speaking, these imperfections are the result of improper understanding and/or teaching, that start out as tiny bad habits, eventually to become glaring weaknesses. This is why accomplished martial artists still listen to constructive criticism. It is why the best athletes in the world still rely on professional coaching.
In this case, dishonour could be interpreted as a lack of humility among one's peers. Or in the misjudged abilities of an adversary.
It could be rooted in a dishonest self-perception, individually, or as a society that puts humanity on a pedestal separate from the natural world.
This is why all actions are best examined closely, lest regret becomes the growing scar on the tree.