In trying to stick with  use strict;use warnings I have had to add a whole bunch of my's and locals. (My dirty secret is I have yet to use local...but I digress)

I'm not one for doing something, "because everyone does it that way."
What started my questioning is the following slice of code
open( HANDLE, "<file");
while( my($line) = <HANDLE> )
{
   print $line;
}

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There are probably a few people out there that have no idea why the above segment is wrong (besides error checking, or doing something truly useful in the body of the loop).
I learned to code using C/C++ so it is stuck in my head to use parens everyplace, it just makes things safer...well in C++ at least :)
Here it evaluates $line in a list context, and eats the file so that I only get to process the first line, then exit the loop. Very much not what I wanted.
I have many scripts that I have coded with a line like below at the top (or at the top of a sub..etc..)
my($var);
my($othervar) = 43;

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Based on my background this looks good to me, but now that I have done some research I don't think it is correct. The correct lines should be:
my $var;
my $othervar = 43;

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That does assume we don't want to declare multiple items... 
my($var1, $var2, $var3);

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1. So my questions are, what other nuances are there with my that have either been Gotcha's or could be?
2. Am I wasting memory/speed/other when I declare using parens on a single scalar (building a list only to throw it away?)

While I have you...what is the differences between my and local? my gives "lexical" scope, local gives "dynamic" scope. In the perldoc -f local it says:
 "You really probably want to be using `my' instead,
  because `local' isn't what most people think of as
  "local"."

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Assuming I'm most people, what do I think it means? What does it really do? Why DO you want to use it?
I would assume you want to keep variables in the smallest scope possible, so the memory/stack is given back to the system as soon as it is not needed.

Thanks for the enlightenment!

In reply to nuances of my, and maybe local by Helter

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