It's really not a lot to grok, at least by most other language's standards.
PHP has a long history of doing things in a "right way" that subscribes to copying whatever one language is doing for 5 years. It first did things the C way, then the Java way, then got inspired by Ruby and Javascript, etc. The features are there, but executed in very awkward ways.
Ruby as a language explicitly blesses many ways to do the same thing.
Every new release in C# seems to bring in as many features as you'd get in 4 or 5 major Python or Java releases.
I look at the Python I wrote 8 years ago and it's _fine_. Even Python 2.6 code written with large frameworks looks similar enough to modern Python. The same can't be said for Javascript, Java (Java's best practices have changed a lot since then), C++, or C#.