Think of layers as tags or classes applied to objects rather than places objects are in/on. For instance you can’t cut something, change active layer and paste it “there” for it to be “on” that layer. When you paste something it retains its associated layer, regardless of active layer. Changing active layer doesn’t take you “into” that layer; it merely changes what layer is applied to objects made by the drawing tools. Double clicking on a group or component on the other hand actually takes you into it and allows you to draw within it.