MyNested is the static nested class of MyOuter. Hence it's just behaves like a static member of the class MyOuter. Since to access the static member of the class you need to access it with the enclosing class, same thing is happening here.. to access MyNested you need to enclose it with MyOuter.
Refer Ch-8 K&B for more details
"History would be kind to me, for I intend to write it."