Nicknames for Given Names (was: sharing an unimportant discovery ...)

[karenoc1]

No: HPFGUIDX 102043

I haven't been able to tune in lately, so I apologize in advance for 
the belated response to this!  And please forgive a post about a nit-
picky topic!  But I've always wondered why JKR, who clearly spends 
quite a bit of time considering details, chose to give characters 
nicknames for given names.  I'm thinking of Harry, but primarily of 
Percy Weasley.  We know that Harry's complete name is Harry James 
Potter, and I can't remember Percy's middle name, but I believe he 
provides his complete name in OotP (alas, I'm bookless).  I remember 
thinking it odd that the Weasley's did not name Percy "Percival."

My mother-in-law was a professor of nursing.  One of the positions 
she held before she began teaching was in pediatrics at a rural 
hospital.  Here, she was known (whether she should have done this or 
not) to steer people away from giving nicknames for given names.  For 
example, she would recommend that the proud new parents not name 
their child Bubba, but name him something like Robert or John and 
*call* him Bubba.  She reasoned to the parents, what if he grows up 
to be a lawyer or a senator?

It seems to me that Percy would be the type of person to resent not 
being given the complete "Percival," especially considering his 
ambitions.  Wouldn't Percy consider his own name to be "common" just 
as Petunia considers Harry's to be?  Am I just thinking too much 
about this?? 

BTW, isn't Molly a nickname for Mary?  Or is she another nickname-for-
name character?

Thanks for letting me finally get this out of my system!!