You've raised a very interesting point - a couple, actually. What rules do we follow, and (probably as important) Why?

I like to think of rules (and following them) as one stage in growth in a language. When I'm brand-new to a language, I tend to be scrupulous about following the rules, even though I often have no clue why a rule is in place, what it's supposed to cause/prevent, what might happen if I didn't follow it, etc. As I learn more, I am in a better place to evaluate which rules, if any, I'll follow. It's something like growing up in real life. Parents can't always explain the reason for a rule - so it's, "Because I told you so." Later on we figure out exactly why they wouldn't let us stick our fingers into the light sockets - often by breaking the rule. Once.

In most other languages, I can go ahead and shoot myself in the foot, no problem. My foot; my choice. In Perl, there is a unique factor that makes me think twice. Perl has CPAN. Suddenly, it's not just my foot we're talking about, but everyone else's who might use a module I write. While I'm still free to blow away my various appendages, there is a strong expectation that I not get overly creative when writing a module that will be shared. This expectation isn't enforced; I can upload crap (as many have done) and CPAN will accept it. But doing so will not endear me to the Perl community. Before I'd knowingly break a rule, I'd run it by the fine Monks here to find out what sort of problems it might cause; or whether there's a way to get it done without breaking that rule.

On my own, of course, all bets are off, and I'll do whatever I feel like... as, I suspect, most programmers do. Programmers do not appear to be the kind of folks who follow rules just for the sake of following rules. Seems to me they're always saying things like, "Gee, I wonder what would happen if..."