If you are really lazy, you can write forwards one line and backwards the next. No more wasted time moving the hand back to just one side. ;o) I also have done the spiral backwards but it bothers me not to have a side margin like I wanted. Top spirals are my favorites now. In college I took calligraphy. Had some trouble with cursive there, even with a leftie quill pen.
Saw some ancient stone-carved writing that went back and forth like that, as the oxen plough. It was in Greek, yet, which we normally see just left to right. Apparently the rules have always been flexible. Those who carve writing into stone are probably not particularly lazy unless that's all they do.