"Perfect Day" (Lou Reed)

Lou Reed—God rest his soul—was a curmudgeonly prick who was notoriously tight-lipped about the meaning of his songs.  But, damn, the man could write some memorable songs.
Over the years, I've read countless articles and people's web musings about the meaning of "Perfect Day."  One popular assertion is that it's a song about trying to kick heroin addiction.  But I don't really buy that theory.  Just because the film Trainspotting used it in the scene where Ewan McGregor's character, "Mark Renton," o.d.'s on heroin, doesn't make it a smack song.
The more plausible explanation is that Reed had fallen in love with cocktail waitress/aspiring actress Bettye Kronstadt—someone who was pretty far removed from the world of Andy Warhol's Factory and the various characters (transvestites, hustlers, junkies, socialites, and fame-seekers) that he had rubbed elbows with.  Thing was, he didn't really know what to make of Kronstadt, a nice, straight-laced girl who took him to sip sangria in Central Park, feed animals at the zoo, or go watch a movie like a "normal" couple.  He obviously found a certain comfort in going home to their love nest at the end of an evening rather than hitting the streets, looking to score drugs and/or sex.  Yet at the same time, he felt a bit disquieted at the prospect of domestic bliss; it's just not who he was.  
There's that heartbreaking stanza toward the end of the song, where he sings:
Just a perfect day
You made me forget myself
I thought I was someone else
Someone good 
Not to mention the very unromantic line he repeats at the very end: You're going to reap just what you sow.  Whether he's acknowledging to himself that the bliss is not going to last, or warning her that she's only going to get hurt, it is Reed at his cruelest (and that includes the sailor getting shot at the debauched party in "Sister Ray" and the partygoers being more worried about his blood staining the carpet than him dying from a bullet wound).
For me, the juxtaposition of sentimental strings against his self-analytical, very unsentimental musings make it less of a ballad about an idyllic day with a sweetheart and more of a commentary about the inevitable destructiveness of hypocrisy and self-deceit.  If there's anything Reed could do, it's tell the blunt, unvarnished truth.