Memorizing perldoc shows you can memorize stuff. I prefer to have a general grasp of perldoc, so that I know what's out there and where to find the details. perldoc exists so that I don't have to remember what's in perldoc.

IMHO, becoming a good Perl programmer is more about becoming good at programming than at Perl. If I was hiring someone into a senior position, I would be looking for the following (in no particular order):

• Do you write tests?
• Do you use SCM? Do you have opinions on which SCM to use?
• Do you code in such a way that you have to think about less things at one time?
• Do you enjoy code reviews?
• Do you look for requirements and design reviews?
• Do you have an opinion on source code structure?
• Can you solve any given programming task in at least two completely different ways?
• Do you have an OSS distribution (in any language hosted anywhere)?
• Are you willing to argue your point in the face of everyone else? Can you do so without cussing?

As I answered "Yes" to more of those questions, I realized I was improving as a programmer. As I add to that list, I know I'm learning more about what a good programmer is.