The way I thought about the strikeout was he's not starting from scratch (as the 4 lines are a sensible progression of thought), but while he's doing it, writin

The way I thought about the strikeout was he's not starting from scratch (as the 4 lines are a sensible progression of thought), but while he's doing it, writing down the letters, he's running ahead in his mind to the next thought. So he thought the lines, but his fingers missed copying down the second line, and ran ahead to the third, and when he realized he struck it out. And copied down the second line which was supposed to be there. Alternately as he's writing it down, through the act of putting it into an ordered form he realizes the thought needs additional qualification to reflect his idea, so strikes it and inserts the second line. I get where you're coming from with the deliberateness, maybe like a todo list of set of instructions. But I just think this matches with the relationship part, and his sort of organized, but reaction/emotional personality. Why would a spy/operator write a secret code in some book of poetry, then chuck it in a car? Seems more like an act of passion. :p :) xx