I got started when I was my employer's "internet expert". This was back in 1994 or so, and "internet expert" meant that I'd used email when I was at university and had once seen (but not used) a web browser. I was given a task to put a local estate agent's listings on this new-fangled "world wide web" and provide a way for interested customers to contact the agents. This led me to Matt's Script Archive and the infamous formmail, and to some of his other stuff too. Of course, as requirements grew, those scripts didn't *quite* do what we needed, so I had to update them, and that's how I first learned perl.
I then later learned perl *properly* by ending up using it a *lot* a few jobs later and through getting in contact with the rest of the perl community via comp.lang.perl.misc and then being one of the founder members of my local Perl Mongers group.
Perl wasn't my language of choice. After my initial dabblings, I then got seduced by Java, and the job I really learnt perl in was one where I was originally employed to be a Windows NT admin and Java programmer - and did neither, as I was immediately put onto a perl project running on Solaris, which I ended up adminning as well. Perl and Java (and C, and all the other ALGOL-family languages) can all be treated as being pretty much identical, so getting up to speed and becoming a vaguely useful developer took about a week of *using it*. Becoming an *expert* - that took years and I'm still learning.