The last chapter shows that even after his success in the last big charge and his new-found prowess and experience in battle, Henry cannot shake off his earlier cowardice when he first faced war. The duality of his response to his success in the last battle: his feeling of pride but also this lingering sentiment of cowardice, is what triggers his coming-of age as he is able to put the past behind him. Note the way that, after the initial jubilation and swell of pride in his role in the battle, he is haunted by old fears and actions:
Nevertheless, the ghost of his flight from the first engagement appeared to him and danced. There were small shoutings in his brain about these matters. For a moment he blushed, and the light of his soul flickered with shame.
In particular, he reproaches himself for his abandoment of the tattered man. However, it is looking back at both his achievements and his failures that allows Henry to put his life into proper perspective.
And at last his eyes seemed to be opened to some new ways. He found that he could look back upon the brass and bombast of his earlier gospels and see them truly. He was gleeful when he discovered that he despised them.
Thus we can see that the memory of Henry's earlier actions is not a negative thing. He has to integrate all of his actions, both good and bad, into who he is, and when he is able to do this, he realises that he is a man who has grown up.