I agree that the song is about a break up, but I've taken a more macabre approach to explaining it. I interpret "One more for the night, One more for the pain" as being one more time he is alone due to an argument, and the same for the pain...In other words, the feeling is nothing new, even though this time the break up is final. "One more long goodbye" could refer to the fact that the breakup was drawn out and their goodbyes were lengthy, and now in contemplation of suicide he once again says goodbye to his ex lover, as well as everyone/everything else. "One shot to the brain" can be interpreted as blatantly literal, and a contemplation of a way to carry out this final goodbye. "One more takes the knife" Another thought of self inflicted harm with a knife. As he sits in misery caring about his mistakes and still longing for his ex, She is getting on with her life ("One more takes the train") So as she is living and pursuing her life, he is ending his. In the second to last repetition of the chorus, I believe the word "train" is changed to "blame" (Listen carefully to the song) which would tie in perfectly to this because she would indirectly be the cause of his death, with the likelihood of her feeling some guilt toward it. "I can't define my right from wrong" expresses his confusion, allowing this interpretation to be possible, even if it is not the most practical.
I agree that the song is about a break up, but I've taken a more macabre approach to explaining it. I interpret "One more for the night, One more for the pain" as being one more time he is alone due to an argument, and the same for the pain...In other words, the feeling is nothing new, even though this time the break up is final. "One more long goodbye" could refer to the fact that the breakup was drawn out and their goodbyes were lengthy, and now in contemplation of suicide he once again says goodbye to his ex lover, as well as everyone/everything else. "One shot to the brain" can be interpreted as blatantly literal, and a contemplation of a way to carry out this final goodbye. "One more takes the knife" Another thought of self inflicted harm with a knife. As he sits in misery caring about his mistakes and still longing for his ex, She is getting on with her life ("One more takes the train") So as she is living and pursuing her life, he is ending his. In the second to last repetition of the chorus, I believe the word "train" is changed to "blame" (Listen carefully to the song) which would tie in perfectly to this because she would indirectly be the cause of his death, with the likelihood of her feeling some guilt toward it. "I can't define my right from wrong" expresses his confusion, allowing this interpretation to be possible, even if it is not the most practical.