What turned Snape (Was: JKR site update SPOILERS)

[julie]

No: HPFGUIDX 158911

<some snippage>

Hickengruendler wrote:
 Snape changed sides, not because he 
> was horrified that Voldie wanted to kill a helpless baby, but 
becaus 
> eit were specifically the Potters he was after. And at this time, 
he 
> couldn't have made any possible connection with Harry. So this 
leaves 
> Lily. The girl, who defended him. The girl he shared Potions' 
classes 
> with, and who was pretty strong in this subject. And yes, I haven't 
> forgotten, that he called her a mudblood. I believe this to be the 
> moment when Lily stopped being on friendly terms with him, and the 
> real reasons, why this was "Snape worst memory". After all, the 
> bullying alone was nothing special for Snape. There were probably 
> several such incidents, so what made this one so special for it to 
be 
> his worst memory?

Julie:
There is a problem with the timeline though. Snape was 15 when the
Pensieve incident occurred. He recorded his notes as the Half-Blood
Prince in his sixth year potions book, which presumably was the 
*following* year when he was 16. I can't recall if Slughorn talks
about Lily specifically as a sixth year student, but it seems 
implied. If so, then Snape called her a mudblood one year, and 
they were partners in Potions the very next year. Were they on
good terms again, one wonders?

Hickengruendler wrote:
> ...also thinking that Snape was "that horrible boy", 
> Petunia mentioned
>

Julie:
I'm thinking the same thing. And for some reason, I'm also 
assuming "that horrible boy" was a teenager at the time or
even a young adult (rather than 11 or 12, for instance). 
So if Snape did come to see Lily, and it was *after* the
Pensieve incident, does this also mean they were on good terms
again? Or was he there to warn her about some danger? Or were
they involved in some sort of project? Did she influence
him in regards to his loyalties? Did he know something about 
her that no one else knew, or vice versa?

Okay, I know these are unanswerable questions right now, but
I feel that there must have been *something* going on between 
them even after the nasty "mudblood" insult. I'm not implying
anything romantic either (even if there was such a feeling on
Snape's part), but something that ties them together in some 
way we're not seeing--obviously because we don't have all the 
necessary information yet! 

Julie, certain Snape's secrets involve Lily, if only because
the final book of a saga always brings the disparate thread
plots together toward a cohesive whole.