Why English is Dumb

Remember in grade school when we were learning to spell? We were taught a few useful little rhymes to help us remember rules. One in particular that I still have to recite when writing is:

Write I before E except after C
or when it sounds like an A as in "neighbor" and "weigh"

So why does the word "protein" get to be the exception? My spelling is atrocious and without spell check and little rhymes I’d look like a complete ignoramus on paper so I absolutely hate words that break the rules.