The Trickiest Thing About Perl (for beginners)

I was recently talking with our awesome UI/UX designer, Ilia, about a problem he was having with Perl. He mostly develops in JavaScript and web technologies, but his front-end obviously has to interact sometimes with the Perl in Webmin. And, sometimes he has to write some Perl, which is not an area he has had any experience with before working with us. Perl can be a tricky language for beginners to the language because of a few quirks that make it behave in seemingly bizarre ways.