A thought popped in my head one night... (Lily and Snape)

[Alex Boyd]

No: HPFGUIDX 112470

Karen L. suggested that Snape helps Harry because he owes Lily for
helping him.

 I know this is a 
> theory that really reaches, but there has to be reasons behind Snape 
> helping Harry out of tight spots....I am always amazed when Snape does 
> help because of his apparent dislike of Harry....

Me (alex):

I don't think Snape needs a Lily relationship to motivate him to help
Harry.  He doesn't like Harry, but he has *plenty* of reason to
understand that being disliked is not a capital offense.  He's not
able to get over his adolescent traumas enough to behave decently
towards Harry in everyday situations, but he draws the line at leaving
him to die simply because he doesn't like him very much.  

Dumbledore says at the end of OoP that he thought Snape would have
been able to put aside his feelings about Harry enough to teach him
Occlumency--this is a reasonable assumption on Dumbledore's part
because Snape *has* put his feelings aside in order to save Harry from
mortal peril in the past.  Why he doesn't this time is up for grabs
(I'd say, either A) Dumbledore didn't give him all the information,
either, just said "I want you to do this."  or B) He just can't handle
the intimacy of looking into Harry's mind and having Harry look into his.)

Alex