Disappointed Lyrics
i wouldn't trust
a single word
i say
i think by now
you should know
nothing's going to change
all of this
theater
i wouldn't waste
your voice
comes a day
you figure out
you never had
a choice
(and I am part of the reason)
what did you expect?
so disappointed
with what you get
do you ever want to
just get out of here
disappointed
disappear
superman
with all the world
to save
you'd think by now
you'd figure out
that nothing's going to change
what did you expect?
so disappointed
with what you get
do you ever want to
just get out of here
disappointed
disappear

It's just nihilistic poetry up to the listeners interpretation. It could have different meanings for everyone. To me it suggests disappointment with mankind, "God", and the world. Also maybe a little sexual inadequacy but that's not the first thing that came to mind.

It seems like this is meant to be something Obama is saying. Read the lyrics that way and it makes a lot of sense to me.
You all expected change but you should have known better than to trust me, a politician. Nothing will change and you'll be disappointed.

I think the song is more introspective than the explanation given about Obama. Trent uses several personal pronouns throughout the song and I odubt he's refering to himself in the third person as Obama. The song is about women building up a hype for reznor based of prejudement before they really get to know him and when they finally get with him it's impossible for him to fulfil the what ever the womens expection that she had of him.
The verse look at you superman with all the world to save you'd think by now you'd figure out that nothing's going to change
Is about someone trying to change or fix reznor, but what did they expect? After all these years did you actually think he would change, then they are disappointed.