Why did Snape call Lily a 'Mudblood'?

[Carol]

No: HPFGUIDX 177557

"Jen Reese" wrote:
>
> Wow, it's a slow list day! I've got a question for a slow day: why
*did* Snape call Lily a Mudblood?  Also, I'm curious how others read 
Snape's Worst Memory given his new memories in DH.  Did the resolution
work for you?  I'm on the fence about this part.
> 
> Jen, playing kid chauffeur at the moment, waiting for a b-day party
to finish.
>
Carol responds:

My impression is that he was humiliated to be "rescued" by a girl he
liked (or probably, being a boy, by any girl). He didn't want her to
see him like that, let alone try to help him, so in his anger (which
was mostly at James and misdirected) he called her the worst name he
could think of and immediately regretted it. (I do think, BTW, that in
a fair fight, he could have given James a run for his money, and he
was enraged that he had been caught in such a position, with his own
spells used against him.) Ordinarily, of course, he wouldn't have done
it. I used to think that "Snape's Worst Memory" was Harry's
interpretation, the unreliable narrator at work again, but now I have
no doubt that his blunder and her reaction left him feeling that he
had no friends but the future Death Eaters, and we all know where that
led. (Learning of Lily's death might have been a worse memory still,
but for the purposes of the story and the affect of the incident on
his life, "worst" is probably not an exaggeration.) The narrator
speaks of Severus's "humiliation and fury" and I think that's an apt
description of the feelings that prompted him to shout "the
unforgiveable word" (DH Am. ed. 675). 

I'm not sure what you mean by "Did the resolution work for you"?

Carol, who knows exactly how it feels to say words that you can't retract