I have a theory that if you learn OO with Perl 5 and Moose (and my book teaches that), you'll find Java tedious, limited, and annoying.

I've split my paid work between OO programming in both languages this year, and Perl 5 and Moose are really that much better. Java's only advantage (to me as a programmer) is IDE support due to partial compilation, but once you bring in things like Spring to deal with Java's inflexibility and lack of abstractions, part of that goes away.

You can write a lot of great Perl 5 code while only ever using objects (so you ought to know enough to be able to use OO modules), but OO Perl 5 gives you a lot of other options to solve problems—especially in testing and design.