Why is everyone surprised at Harry's Patronus?

[sofdog_2000]

No: HPFGUIDX 77517

--- In HPforGrownups at yahoogroups.com, Fred Uloth <prof_uloth at h...> wrote:
> At 11:46 PM 8/14/2003 +0000, Pruneau wrote:
> >But he chose the Patronus, so I assume that very few people  (only
> >Lupin, Hermione, and maybe Snape, Ron and Sirius) knew it was a
> >stag. So IMHO, the Quidditch Patronus was just a (large) silvery
> >wisp of vapour.
> 
> Actually, at the end of PoA Dumbledore remarks on noting the curious form 
> of Harry's patronus at the match after he learns of James's Animagus form. 
> So by that point in time Harry's Patronus was a stag and had a form...else 
> DD could not have noted it and seen the connection between the patronus and 
> James.]

Sof:

Also, Lupin was shaken when he congratulated Harry after the match. He must also 
have been surprised to see it was James' animagus form. You don't choose the 
Patronus' shape. Harry didn't know what shape it was until he'd gone back in time and 
cast the Patronus from the far side of the lake.