Most OOP courses do not teach OOP from the perspective of prototype inheritance.
The extreme mutability of JavaScript and its consequences are also not well understood by most.
The consequences of IEEE 754 as numeric type are also not well understood among JS enthusiasts.
The distinction between creating/compiling a regular expression and evaluating it is also rarely covered.
The way it is implemented by vendors, using tricks such as pre-tenuring, hidden classes, shapes, inline caching, JIT, etc... also not widely understood.
The JavaScript sections of Stack Overflow are the blind leading the blind. Many widely used libraries are also written by the blind leading the blind.
The extreme mutability of JavaScript and its consequences are also not well understood by most.
The consequences of IEEE 754 as numeric type are also not well understood among JS enthusiasts.
The distinction between creating/compiling a regular expression and evaluating it is also rarely covered.
The way it is implemented by vendors, using tricks such as pre-tenuring, hidden classes, shapes, inline caching, JIT, etc... also not widely understood.
The JavaScript sections of Stack Overflow are the blind leading the blind. Many widely used libraries are also written by the blind leading the blind.