Here's a Jekyll
If Tom Jackman and Mr Hyde don't have each other's memories,
how does Hyde know how to drive a car, whistle tunes or use
Tom's bank cards (I assume Tom doesn't leave lots of money
in his pockets for Hyde to spend)? How can Hyde know how to
do even the most simple things, like walk, talk or have sex?
Where does this knowledge come from?
in two minds about this!
It's likely that some fundamental learned behaviours, such
as walking, talking and having sex, are "hard-wired" into
the brain. For this reason, people with amnesia can usually
still walk, talk, read and write, even if they can't remember
their own name or where they live, etc. The fact that Hyde
is accessing basic memories that were learned early in Tom's
life might also explain his more pronounced accent - this
is Tom's accent from his youth, before he moved to England
and his dialect became diluted. Hyde could have learned more
complicated information and skills, such as how to use a computer,
later on after his emergence.
it could be that Hyde is only denied information (on a subconscious
level) that is specifically related to his split personality.
So he knows how to walk, talk, read, write and drive a car,
but he cannot access memories to do with Tom's identity, his
address, the people he knows, and so on.
How Hyde obtains money is an interesting point, which is worth
dealing with separately. I doubt that he can use Tom's bank
cards, because they would require PIN numbers, which is the
kind of memory Hyde is not able to access. Being the kind
of guy he is, Hyde would probably mug a stranger or rob a
cash register if there were insufficient funds in Tom's pockets.
In order to keep his alter ego out of that kind of mischief,
I reckon Tom would either ensure that he leaves plenty of
cash in his pockets for Hyde to spend, or he might even set
up a special bank account for him.