A theory of Lupin's transformation

[Irene Mikhlin]

No: HPFGUIDX 51010

We went many times through all the explanations as for how Lupin could 
have forgotten his potion and was not reminded by Hermione's guess or 
even by the prank memories. And frankly, none of the explanations was 
completely satisfactory. I believe this theory was not presented before, 
so here it goes:
Let's start with the episode in the "Flight of the fat lady" chapter
(p.118 of UK hardcover):
"I made an entire cauldronful", Snape continued. "If you need more".
It follows that the potion dose is not fixed, and that Lupin somehow can 
determine the correct dose by himself. How he does it? It might be some 
physical characteristic, but more interesting would be if the dose of 
the potion is determined by his emotional state.
The whole year Lupin makes a point of being perfectly polite and nice to 
everyone. What if the potion is counteracted by patient's feelings of 
anger, hate, murderous rage or similar dark emotions? That would explain 
his transformation without making Lupin senile or in deep denial about 
his illness. During that evening he experienced some hard feelings 
towards Black, then Pettigrew and finally Snape - probably enough to 
neutralize twice his normal dose.

So how was that for Lupin's apology? :-)

Irene