I'm not crazy, I'm just a little unwell. I know, right now you can't tell.
But stay awhile and maybe then you'll see,
A different side of me.
I'm not crazy, I'm just a little impaired. I know, right now you don't care.
But soon enough you're gonna think of me,
And how I used to be...

It's from Matchbox 20. Right on the money..