Lazy collections have the following properties:
*Any operation, even an add, causes the collection to be loaded.
*When the collection is loaded, all elements are loaded at once.

Extra-lazy collections have the following properties:
*Some operations, such as add, do not cause the collection to be loaded, or even counted.
*Elements of the collection are loaded individually, as needed.

Since it's possible for elements to be added to an extra-lazy collection without loading, or even counting, the collection, why does adding elements to a lazy collection force loading?