Throughout its reign, the dominant order of reading dictated certain rules about how to read in a civilized manner… They proclaimed that the reader must be seated in an erect position with his arms resting on a table and the book in front of him. Reading must be done with maximum attention, without moving, making noise, annoying others or taking up too much space. One should read in an orderly fashion, following the text section by section, turning pages carefully without rumpling them or folding them down and without mistreating or damaging the book… according to these principles and models, reading is a serious and demanding activity requiring effort and attention… Other modes of reading (alone, anywhere in the house, in total liberty) are of course known and even acknowledged, but as secondary; they are grudgingly tolerated, but felt to be potentially subversive (Armando Petrucci, A History of Reading in the West)
Serious and demanding: yes. Reading is certainly this. But to impose rules upon reading undercuts the seriousness of the endeavour. It makes reading just another silly ritual, like passing port to the left, or standing for the national anthem. The more subversive the reader, the more serious. One does not engage by being orderly. Take care, by all means, but take care not to be too polite. Be serious about your carelessness.