[HPforGrownups] Interesting throwaway on Hermione at JKR's updated site (dragon's blood)

[P J]

No: HPFGUIDX 149374


SSSusan:
"...and Hermione Granger (cleverest girl in the year and the only
person in the class to know all the uses of dragon's blood)."

PJ:
I didn't expect only Dumbledore to know the 12 uses because, like any other 
invention, it needs to be known by many people who can put those discoveries 
to good use.  Otherwise what's the sense of spending all that time working 
on the problem?  And Dumbledore likes people to know just how smart he is.   
   :)

What surprised me was that it didn't say the only *student* in the class to 
know, but the only *person*.  Is this said differently in the UK than in the 
US or does this mean teachers as well as students?  If so, I wonder who's 
class she was in and how many teachers are still ignorant of the uses?

PJ