Take 2 fantasies and a delayed main verb...

Some writers definitely have a formula, even if they aren't aware of it. As Aristophanes pointed out in The Frogs, Euripides opens prologue after prologue with a sentence in which the main verb is delayed by a long subordinate clause, while Aischylos has a habit of leaving a main character onstage for yonks without saying anything.

It's true of poets too, as occurred to me while at a Simon Armitage reading yesterday. I'm not saying they do it all the time, but they do develop habits of composition. For instance, Billy Collins, in whose Ballistics I've been happily immersed, has poem after poem in which he sets out his stall and then, right near the end, introduces a "but" or "however" that changes the poem's direction and partially undermines what has already been said. "But for now I am going to take a walk" (The Poems of Others), "But what truly caught our attention" (Scenes of Hell), "but I am here to remind you" (Adage).

That's a syntactical tic: Armitage's is more a compositional one. A lot of the poems at this reading were constructed on the basis: "this fairly dull thing happened to me, but what if it had gone off at tangent x", whereupon he follows Cpl Jones off into the realms of fantasy. I don't recall this happening so much in his early work, but you could almost predict when the veering-off-into-fantasy is coming now.