For years, Newton's third law has always bugged me. Sure, on some level I could believe it. After all, it must be true else I wouldn't be able to jump off the ground. But it always seemed extremely counterintuitive that an inanimate object with no muscles or battery or other power source could produce a very real force.
Recently, I've been revisiting the issue, and had a major revelation when reading this brilliant answer by @Rocketmagnet, which essentially describes Newton's third law as it applies to fundamental forces.
Once you accept that, for example, the repulsive forces associated with electromagnetism always come in force pairs, and that the force is inversely proportional to the (square of the) distance between two "objects", then the reactive forces we experience in our everyday lives make complete sense. Sure, my muscles may be providing the energy to drive the contact point, between my foot and the ground, closer and closer together, but that is completley incidental. What matters here is that, as a result of the decreased distance between my foot and the ground, the electromagnetic repulsive force is increased. Crucially, this force has no privileged membership to either my foot, or the ground - it is an interactive force between them.
Yet, I get the impression that when Newton's law is first taught, it is not taught in terms of (fundamental) force pairs (whose magnitude depends upon distance). Rather, it is taught in the standard "If you push on a wall, the wall pushes back". Parity at this high level description no doubt confuses many minds, as it seems to impute a physical agency to the wall. Trying to resolve this confusion by simply saying that things come in force pairs seems to be an arbitrary explanation that has no deeper meaning.
Yes, I do understand that on some level, even the deepest explanation may seem arbitrary and meaningless, but for some reason, I at least find it much easier to accept the idea of force pairs when it is presented in the context of fundamental forces and distance between objects.
So, two questions:
1) Is my understanding of the law correct?
2) Is there a reason that it is not usually taught this way?