Why do object-to-array casts return "mangled" property names, while some properties may become entirely inaccessible? Why are property accessors (like `__get` and `__set`) much slower than ordinary method calls? Why do objects become larger when you loop over them? Why are exception backtraces not always accurate?
Sometimes, internal details of the PHP implementation leak into the language, manifesting either as unexpected results or unusual performance characteristics. This talk seeks to explore some of the darker corners of PHP and explain how certain behaviors relate to the underlying implementation.
Takeaway: A better understanding of both PHP, its implementation and its performance characteristics -- albeit probably not much that is directly applicable to your average project. But hey, language trivia is fun!