When I was at school, learning by rote was part of every day - remember those history dates, and the times tables. The rule 'I before E except after C' was something that stayed with me all my life.
It was only recently that I realised this "rule" was complete rubbish, as there are so many exceptions it is a complete waste of time. How cheated I feel. I had to look up the word their and quickly found the rule to be at fault.
Further research proved the weakness. For example, what about science ?
There are so many others, I will get cross listing them all, but how many exceptions can YOU think of ?
So as you will gather the rule is a joke, and I wish I could find that English teacher and tell him so!