Let me give you an example.
The weirdest part about this isn't even the closure. The closure is fascinating, but the more stupid part is that first semicolon. How do you explain that to someone? Well, you see, child, some people's code is absolute shit, and someone might take your code and try to compile it with other code, and if the other code is bad, it will break your code, so you should just put in a little insurance to break their code before their code breaks your code.