Two of the very few poems I've written as an adult are sonnets. They're not good (none of my poetry is, and I know how much work it would be to make it better) but in working on them I discovered something I hadn't known about how writing happens. When you're writing anything creative, you have, by definition, to put words in an order they've never been put in before. But our sense of what words go well next to each other is mainly based on sense, on logic, on combinations of words we've heard before, and so getting beyond that, to wherever truly new things come from, is hard to do.
One of the most interesting 'how to' books I've ever read about writing isn't about writing at all, it's Drawing on the Right Side of the Brain. It introduced me to the whole notion that logical progression is only one way the brain can work, and when it comes to reproducing what we perceive, to producing things which are more than the sum of their parts, not always the most useful one. Betty Edwards maintains that it's our logical, left-brain, conceptual sense of how things 'ought' to be which hampers most of us in directly setting down lines which express what we do actually see. For example she gets her students to turn a portrait upside-down and then copy it, to circumvent their idea of how faces 'look'. I know many artists who look at their work in a mirror on the same principle: to see directly, intuitively, right-brainedly what's actually on the canvas.
A sonnet, I needn't tell any readers of this blog, is very closely defined. Meter and number of lines are both prescribed, though there are a few - very few - different rhyme schemes you're allowed. And, paradoxically, this strict, Rennaissance form, like other strict forms, continues to fascinate real poets (as well as the likes of me). I think that one reason is that strict forms can be very liberating. The thing about rhyme or any other restriction of rhythm or sound is that, like turning a portrait upside-down, it sets up a different search criterion for one's brain, a different kind of 'understanding' and not one that's based on the meaning of words. So in searching for the appropriate rhyme-sound (or alliteration, or dactyl, or any other aural element) our minds turn up all sorts of words that a logical search - as in a thesaurus, say, where logical connection is the whole point - would never have produced.
If you don't believe me, try dipping into a rhyming dictionary. Three syllables with the rhyme sound -EN, for example, gives you, among others: oxygen, halogen, prairie hen, Magdalen, cyclamen, specimen, partimen, gentlemen, poison pen, Saracen, mise en scène, denizen, citizen. I don't know about you, but already my mind is beginning to try fitting some of those together, and some very odd and interesting images are the result. Not, for me, a poem (though some of the lists have the magic of found poetry) but as a starter for a story, perhaps. Either way, I don't think reason would have come up with anything like the things that rhyme has.