I think it's just forshadowing their breakup. I think at the beginning, he's thinking about how this relationship won't last. And "The mindless comfort grows when I'm alone with my 'great' plans" means he's thinking of what will happen after this relationship ends, but he knows it won't be good without her. And then the second part of the song is her breaking up with him. "'If I'm not happy now then when?'" means she's no longer happy with him and needs her space or whatever. But he's just thinking about how it all will end when it does. I dunno. I like your meaning, too, SiameseDream.
I think it's just forshadowing their breakup. I think at the beginning, he's thinking about how this relationship won't last. And "The mindless comfort grows when I'm alone with my 'great' plans" means he's thinking of what will happen after this relationship ends, but he knows it won't be good without her. And then the second part of the song is her breaking up with him. "'If I'm not happy now then when?'" means she's no longer happy with him and needs her space or whatever. But he's just thinking about how it all will end when it does. I dunno. I like your meaning, too, SiameseDream.