It just seems flatly impossible. You persist only because you know it must have been put on at some point in the past, and in theory every sequence of moves ought to be reversible. But if you’re me, at least, eventually your mind starts to doubt even such unassailable logic, and you begin to entertain the idea of cutting the frame away and welding it back later. I get so focused on the problem at hand that, outside my tunnel vision, a wholesale insanity begins to sprout in support of my immediate goal.
