[HPforGrownups] Why is everyone surprised at Harry's Patronus?

[T.M. Sommers]

No: HPFGUIDX 75993

Jonathan wrote:
> For example..  OoP 16/342 (US) it sounds like a big secret that 
> Harry can cast a Patronus.
> 
> But, in PoA 13/262, Harry casts a Patronus *in the middle of a 
> Quidditch match*.  You'd think a few Hogwarts students might have 
> noticed then.

I would guess that most everyone was watching the match, and not 
paying attention to the ersatz dementors.  Most of those watching 
the match would be paying attention to the chasers and the 
quaffle, too, so they would not necessarily see Harry use his 
wand.  Additionally, some students who may have seen the patronus 
might not have known what it was.