The other Zamenhof poems on the course are public: an anthem, a call to the brothers, a road. This one is private. A summer evening in the fields, a girl singing about hope, and a man who has gone so quiet that she asks whether he is asleep. He is not. He is thinking about what the language has cost him, and the third stanza says it outright: his youth, , laid on , the altar of duty.
Zamenhof printed it himself, in the Fundamenta Krestomatio of 1903, beside Al la fratoj, La vojo and Ho, mia kor', so the text is his own and not a later editor's.
Listen for -, the prefix of doing it again, three times in five lines: (a memory, re- plus memori), a (struck again) and resangante (bleeding again, from , blood). The last two are built on the spot, which is the point: you have never seen them and you can read them.
And the -ante words, , resangante, are the adverbial participle doing what it does best, saying what someone does while doing something else. Participles covers the full set.