A fine node with one mistake:
prints "blah\blah". To put a literal \ in a Perl
single-quoted string, you should use \\, just
like with double-quoted strings. If the character after
a \ (in a single-quoted string) doesn't happen to be ' or
\, then the \ is preserved. But using this fact often
leads to confusion like the mistake in your post, so I
discourage people from doing that.
I really wish Perl had used '' (two adjacents 's) to
quote ' inside of 's. But my time machine is broken.