A newly created environment has no imports and no exports. If you compile a method (or doIt) in such an environment, all bindings will be undeclared, and if you import it into another environment, none of its binding will be visible.
To be able to resolve bindings inside the environment, you need imports. #importSelf tells the environment to import its own contents, to make classes and globals defined in the environment visible to methods compiled in the environment. #exportSelf tells it to make all its contents visible to the outside world.