Supernatural, Season 4

Sam:
You want to know why I've been lying to you, Dean? Because of crap like this.

Dean:
Like what?

Sam:
The way you talk to me, the way you look at me like I'm a freak!

Dean:
I do not.

Sam:
You know, or even worse, like I'm an idiot! Like I don't know the difference between right and wrong! What?

Dean:
Do you know the difference, Sam? I mean, you've been kind of strolling a dark road lately.

Sam:
You have no idea what I'm going through. None.

Dean:
Well then enlighten me!

Sam:
I've got demon blood in me, Dean. This disease pumping through my veins and I can't ever rip it out or scrub it clean. I'm a whole new level of freak! And I'm just trying to take this - this curse... and make something good out of it. Because I have to.