What happens to a person's pensive after they're gone?

[justcarol67]

No: HPFGUIDX 143693

CMC wrote: 
> Actually, Snape is not shown with his *own* Pensieve - when Harry 
> enters Snape's dungeon to begin his first Occlumency lesson, Harry 
> notices that Snape has *Dumbledore's* Pensieve:
> 
> "<snip> Harry's attention was drawn towards the desk, however, where
a shallow 
> stone basin engraved with runes and symbols lay in a pool of 
> candlelight. Harry recognised it at once - it was Dumbledore's 
> Pensieve. <snip>" 

Carol adds:
Moreover, Snape apparently puts his memories back in his head after
each Occlumency lesson since Harry sees him take out three memories
each time. Although JKR implies in an interview that the Pensieve is
used for storing memories, her main concern is answering the question
about the objectivity of those memories, not what happens to the
memories after they've been "used."

DD uses the Pensieve in GoF to figure out who put Harry's name into
the Goblet, studying his memories of Barty Crouch Sr., Karkaroff, and
Alastor Moody, as well as related matters like Bertha Jorkins, to
solve the mystery. Snape in OoP uses the Pensieve simply as a place to
*temporarily* store his memories during the Occlumency lessons. Almost
certainly they're not still in there when he returns the Pensieve to
DD (as we know he does because DD has it again in HBP) after the
Occlumency lessons fail. Also, the Pensieve seems to be *empty* when
Snape puts his own memories into it, meaning that DD's memories,
having served their purpose, have been removed. By the same token,
each time DD puts a memory (from a vial) into the Pensieve in HBP, the
other memories seem to have been removed, so that Harry and DD enter
only the specific memory that has just been placed there.

IOW, the Pensieve is not like the orbs that store(d) the Prophecies in
the DoM. It's not meant to store memories longterm. Almost certainly,
they're returned either to the head of the person the memory belongs
to, or, if that's someone other than DD or Snape, to the vial from
which DD retrieved them. If that's the case, none of Snape's memories,
and probably none of Dumbledore's, would remain in the Pensieve
itself. Quite possibly, however, some of them would have remained in
their labeled vials and McGonagall would know where they were stored.
Giving Harry permission to access them would be quite another matter. 

Supposing that DD has willed Harry the Pensieve to examine his own
memories, particularly Godric's Hollow, there's still the matter of
knowing how to use it. If, as some people suspect, Lupin is a
Legilimens, he might be able to extract that memory from Harry's head,
but Harry doesn't know how to do so himself.

Which reminds me--maybe the Pensieve is the answer to the missing
twenty-four hours and how DD knew that Lily's sacrifice had protected
Harry (and that LV wasn't dead). Just possibly he was able to extract
that very recent memory from Baby!Harry's head and find out what
really happened--except that he didn't notice the presence somewhere
in the background of a certain rat.

Carol