Static variables in C++

Executive summary: Static variables declared in a class in C++ get set up even if there is not a single object of the given class.

Request: Please let me know if there are errors (logical, typographical, or otherwise) in this document.

Microsoft has this to say about a static variable: 

When you declare a data member in a class declaration, the static keyword specifies that one copy of the member is shared by all instances of the class. A static data member must be defined at file scope.

Here is our code for CBase.h

 
#ifndef CBASE_H_
#define CBASE_H_
class CBase
{
public:
 static int x;
};
int CBase::x = 1987;
#endif // !CBASE_H_

Here is our code for Source.cpp where we have our main method:

 
#include 
#include 
#include "CBase.h"
int main()
{
 std::cout << CBase::x << std::endl;
 return 0;
}

Now, let's talk about it for a minute. When, in the run time, do we access anything in the file CBase.h? The answer as far as I know is never. There is only one explanation (that I can think of) is that the integer x gets created during compile time.