In the spirit of the "Perl Monks" theme, here's my take on the "fast enough" question with reference to Zen teachings, here presented as a paraphrased version of the comments of another monk, Takuan Soho, on learning:

You need to realize that when you practice from the state of the beginner all the way to the stage of immutable wisdom, then you must go back to the status of the beginner again.
     Let me explain in terms of Perl. As a beginner you know nothing of statements or regular expressions, so you have nothing in yourself to dwell on mentally. If someone asks you to program, you just program without thinking of anything.
     Then, when you learn various things like packages, how to wield a regular expression, where to place your attention, and so on, your mind lingers on various points, so you find yourself all tangled up when you try to code.
     But if you practice day after day and month after month, eventually statements and structure don't hang on your mind anymore, and you are like a beginner who knows nothing.

Zen teachings advocate a position of doing without thinking, which is to say that only when you can program without thinking about programming can you claim that you can really program at all.

Learning Perl is like learning any language, and you have really only learned that language when you begin to think in that language. You're "fast enough" when you don't have to think about Perl at all and you can just program.