High-school rules of poetry are just basically there to teach you about the basic forms of traditional poetry. For the free-verse person, they are largely negligible.
College tells you how to actually write well; how to express yourself without sounding like an idiot.
I mean, yeah, it's good for free expression, but you don't want to sound like someone who can barely form a sentence as is, right?
A lot of kids think that poetry is either something that rhymes or just a couple of sentences with the 'enter' button hit at random during it. But it's so much more. I like rhyme myself (my favorite poet of that type being WB Yeats), but all free-verse poems, if you look close and study their structure, have a wonderfully rich thought-process behind them. At least the good ones do.
It may be just me, but I find the reasons like that as well as the structures of the poems sometimes just as intriguing as the actual message themselves.