It seems to me that this song is basically about the aftermath of him being left. He is drinking in a metaphorical bar, and I believe parts of the song are written from a somewhat different perspective, seeing as the lines "Drink up so we can both finally die" and "Why did she finally leave? Because all you think of is me" seem to be referencing multiple persons. I believe the second line there, the one which claims "Because all you think of is me" seems to show that it may be written from not a person's perspective, but from the perspective of part of his personality, maybe the part of him that is sad and lonely and scared. I'm not sure, though, all of this is my opinion. I think only Keaton himself really knows!
It seems to me that this song is basically about the aftermath of him being left. He is drinking in a metaphorical bar, and I believe parts of the song are written from a somewhat different perspective, seeing as the lines "Drink up so we can both finally die" and "Why did she finally leave? Because all you think of is me" seem to be referencing multiple persons. I believe the second line there, the one which claims "Because all you think of is me" seems to show that it may be written from not a person's perspective, but from the perspective of part of his personality, maybe the part of him that is sad and lonely and scared. I'm not sure, though, all of this is my opinion. I think only Keaton himself really knows!