I don't think that's it. I'm pretty sure that's talking about variables declared within the subroutine.

Right after the part you mentioned, perlsub says this:

This doesn't mean that a my variable declared in a statically enclosing lexical scope would be invisible. Only dynamic scopes are cut off. For example, the bumpx() function below has access to the lexical $x variable because both the my and the sub occurred at the same scope, presumably file scope.

    my $x = 10;
    sub bumpx { $x++ }
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I thought that since the lexical scope of $x includes the body of bumpx(), any closures created inside bumpx should also have access to $x -- and they do, kinda. But it seems like bumpx() (or foo(), in my case) has to be "reminded" that $x is in its scope, otherwise the inner sub doesn't get access.