How did Harry survive Voldemort's attack as a baby?

[Keith Fraser]

No: HPFGUIDX 10271

What was it that allowed Harry to survive the supposedly unstoppable 
Killing Curse and reflect it back onto the user? In Book 4 Voldemort 
seems to believe that Lily's dying for him both stopped and deflected 
the curse. However, as I have seen pointed out in the past, people 
have probably taken an Avada Kedavra for others before, so there may 
have been something else.

Also, in Book 2 Harry says something like: "Nobody knows why you lost 
your powers when you attacked me. But I know why you couldn't kill 
me. Because my mother died to save me." to Young Voldemort (Tom 
Riddle). I don't know how well-founded Harry's statement was, but it 
suggests the halting and reflection of the curse were separate things.

Fanfic authors (including myself) have put forward various ideas 
about Harry being some kind of super-wizard. The books haven't yet 
shown much if any evidence of this (his resistance to the Imperius 
Curse is a possible clue), and it's impossible to know if that will 
turn out to be the case, but I support this idea. For one thing, it 
means Harry might have a chance of defeating Voldemort once his 
dormant powers emerge, which means the books can end the way everyone 
wants them to - with Kentucky Fried Voldemort.