Why is Slughorn raving about Lily instead of Snape?

[sweetpea57007]

No: HPFGUIDX 133967

Florentine Maier wrote:
> Slughorn must have been teaching Snape too, who has been in the same year as Lily. Wouldn't it make more sense if Harry reminded him of Snape?

I'm very curious about the relationship between Snape and Lily. She 
stuck up for him when James was being a bully to Snape. Snapes response 
to Lily was that he didn't need her help but still he must have 
secretly appreciated that she stick up for him. My pet theory is that 
Snape had a secret crush on Lily and is angry at LV for having killed 
her. If Dumbledore knew about this (if Snape told him that this was his 
reason for turning against LV) then this secret might be why Dumbledore 
trusts Snape. Doesn't it seem as if JKR is trying to make the statement 
that love is more powerful than hate? 

sweetpea