Not all of us farm or tend gardens anymore...
Not all of us farm or tend gardens anymore, so for some, this illustration may not be quite as illuminating as it once was. Perhaps this would serve as a more up-to-date allusion, as incomplete and hokey as it may be: I am currently typing up these illustrations on my laptop. Currently, this laptop is unplugged and running on battery life. While I can perform this task for a while (even several hours, with some of these new batteries), eventually my laptop will cease functioning. Why? Because it is not connected to a power source. (I just had to plug it in, actually!) That is like us.