Metaphorical? (spoilers)

I just finished watching this movie and took the whole story as a metaphor. To me, the presentation of the samurai's belt and the Redbelt were symbolic of the good he did in his life. As in, Mamet did not really intend for this movie to follow a traditional fictional plot narrative. Instead, the ending plays like a homecoming. The only thing I really know to compare it to is heaven. His character lives his life by the "good" code and in the end is rewarded for it, by receiving the highest honor available to someone in his position: the Redbelt, a symbol of immortality. I read earlier on this board that someone relegated this movie to a poem or haiku. I agreed completely, or at least that's the impression I got after my first viewing. I took the movie to be an example of how upholding honor and justice in a corrupt world bears good fruit in the end. I'll definitely be watching this movie again, as it is the first of David Mamet's films I have seen (and will likely be viewing more if they're this insightful and well-put together).

I didn't dismiss the other explanations for the plot after reading about them, however. I can see where a big con could be involved, I just didn't feel that upon finishing the first viewing. I don't know; I'm not Mamet so I don't know what necessarily was going through his head when he wrote this, but that's the sense I got. Almost ethereal, and dreamlike in its execution. Am I the only one who felt this way?