Learning how to spell words that are hard to spell is the bane of students and adults alike. Just when a "rule" is learned, such as "I before E except after C" there are exceptions put in: "or when sounding like A as in 'neighbor' and 'weigh'." Then, some aspiring novelist decides to put in a sentence like "Neither of the foreign sovereigns wanted either of the feisty heifers for protein, and they seized the weird kaleidoscope from the counterfeit poltergeist!" and the rule goes up in a puff of smoke.
Unless the habits of correct spelling are ingrained early on, the incorrect way of writing difficult spelling words will establish itself as a habit well into adulthood.