You can load a plane with a bunch of stuff, but if you load it too far forward or backward, you'll lose that stability. Too much stuff in front, and the nose will never point up and you won't get off the ground. Too much stuff in back, and the plane will just keep pointing further and further up until you stall out, can't recover, and crash to the ground tail first.
What I'd like to decide is if people are inherently stable, and just loaded wrong, or inherently unstable. Because sometimes I feel like I just can't straighten out for any period of time. Turbulence, maybe?
The wright brothers airplane was completely unstable, but somehow accomplished something. Almost none of today's pilots would be able to fly it. Funny thought.