Studying Poetry, and Taking a Study Break.

From my study of poetry so far, I've learned that there are many rules regarding rhyme, rhythm, meter, assonance, consonance, etc., BUT it is the breaking of these rules that really gives life to a poem. My question, then, is why have the rules in the first place.
I am taking a short hiatus from my study of poetry to read Behind the Beautiful Forevers, a non-fiction book about life in the slums and shantytowns of India. I picked it up and have only been able to put it down at mealtimes.
My adventurous life is abuzz now with house guests who will be with us for a week. Our friend is the pastor of a church in central California, and he brought a friend with him to enjoy a week in SoCal, most of which will be spent hobnobbing with other pastors from around the globe who are in town for a pastors' conference at our church.