5.1.1 The start Method

Every class has a start method, which is run at the end of the process of the object being loaded in by Storage. Note that this is run any time the object is loaded, including as a result of upgrade calls. Therefore, start must not assume, well, anything. For example, the start method on a wandering puppet, that starts its wandering from room to room, must not assume anything about what room it starts in.

Note that any initialization of anything that is not completely permanent should happen using the start method, not the init method.