Harry's hatred of Snape

[kateydidnt2002]

No: HPFGUIDX 153828

If this has been address already specifically I apologize and would 
ask if anyone would be so kind as to point me in the right direction. 

One of the things that bugged me most in *Half-Blood Prince* is the 
conversation with Lupin around Christmas ( I believe that was when it 
was) where in Lupin says something to the effect of "You're 
determined to hate Snape and you inherited it from your father." 
(Sorry my book is not with me at the moment.)

WHAT?!?!

How on earth does this line make sense at all? Harry was 15 months 
old when his father died. His one memory of his father was the night 
he died. Other than the physical genetic inheritance he got from his 
father, he couldn't get much else from him because he doesn't 
remember him! There is no such thing as a genetic predisposition to 
hate person X. Harry later learned of the animosity between Snape and 
James at the end of book one in his discussion with Dumbledore. Note 
this: Harry's dislike of Snape started about ten months earlier.

Harry did not in any way inherit James' dislike of Snape--Snape 
managed to engender that all on his own. The only thing Harry 
inherited from his father with regards to Snape was *Snape's* hatred 
of anything Potter--not the other way around as Lupin seems to be 
saying.

Added to this conundrum of why this line in particular is in the 
books is that one of the overarching theme of the whole series of the 
is the importance of choices. As Dumbledore says in book two "It is 
your choices, far more than your abilities that determine who you 
are." Even in book six Dumbledore berates Harry for putting too much 
faith in the prophecy--emphasizing that it is Harry's choices that 
make the prophecy what it is, *not vice versa*. Notice the people who 
are obsessed with traits, rather than choices,  being the determiner 
of worth are Voldemort (I am Slytherin's heir, therefore I must be 
evil), his Death Eaters (all muggles, muggleborns, and muggle lovers 
are bad), and Snape (I hate all things Potter).

So why was this line put in?