Whilst it is a long-standing joke, it's an accurate one. You gotta go right to the horse's mouth be it a properly documented language, or one that has a "specification" that's hard to follow and not even written for the people who are going to use it like HTML/CSS.
I've lost count of the number of times I've seen garbage mistakes in PHP from "advanced" developers who quite clearly have never ONCE visited php.net
See the giant red warning boxes about mysql_ functions that have been there for nearly a DECADE now. If people had bothered paying attention to that maybe they wouldn't be running around like chickens with their heads cut off now that PHP 5.6 throws warnings and PHP 7 doesn't even have them -- or WORSE staying on hosting that is deploying insecure, outdated, and no longer receiving updates versions of PHP. There is NO reason for anyone to be deploying anything LESS than PHP 5.6 apart from codebases over a decade old mixed with developer ineptitude and a equal measure of laziness.
MOST of the problems having been easily avoided if you bothered to -- SHOCK -- RTFM!