When training elephants, keepers begin a very small elephant on a huge, heavy chain connected to a deep-driven peg.  The small elephant learns it is useless to try to break away.

As the elephant grows, keepers use the same shackle, but a smaller and smaller chain attached to a shallower and shallower peg.  The keepers no longer need the heavy chain or the deep peg.  The elephant has learned that it is senseless to fight and pull against such a chain.  It learned this when little, and the shackle still yields the same results for this 9,000-pound elephant that could easily walk away with the chain and the peg (and the keepers, too!).

Could this apply to the reluctance of some parents to begin homeschooling? What invisible chain holds them back? If they only knew how much power they had to break away!