Frankly, for a beginner (which is ostensibly one of our key target audiences), I would encourage doing a thing already done, so you can compare how you approached the problem to those who have come before you.

Most people learn by doing; or, perhaps more accurate to say that they cement their learnings by doing.

So I, for one, take the opposite stance: It is vitally important for most beginners to do many things already done. That's how they develop their art.

Plus, on the everpresent practical note, sometimes you can't use CPAN modules. We've hashed that over and over here at the Monastary for years; but the truth is sometimes you don't have the option to drink deeply from the CPAN well.

At which point you need to have your art reasonably well-developed, as you will be re-inventing that wheel, and it sure would be nice if you made a decent showing of yourself in the process.