About a year ago, I did the Brainbench Perl certification test. A year ago, I didn't know OO, almost never used references and never used strict or -w. I didn't even know that local didn't declare. But I passed the certification. At master level.
(Please note that a LOT has changed in the past year - in that year, I read most of the documentation in the distribution, read a lot on regexes and skimmed over some ORA books I borrowed. (I bought MRE, though - couldn't find anyone that had it). I think my own code is quite good, but then again, I have always thought that ;))
2;0 juerd@ouranos:~$ perl -e'undef christmas'
Segmentation fault
2;139 juerd@ouranos:~$