Whilst I wouldn't say it was a prerequisite at all, because of its Unix heritage understanding something of Unix does help in a number of ways, firstly why some of the builtin functions are named strangely such as unlink and grep is quite obvious to someone who has worked with a Unix-like operating system, but can be opaque to others, and secondly that the Unix toolbox mindset does pervade a lot of the design of Perl and the way that people think about using it, though you find people talking about this less these days as people seem to make large applications and libraries that do more rather than lots of small things that do one thing really well and can be combined with others to perform a more complex task.

/J\