Perhaps we should form a 'symmetry' group to promote 'equality of appearance'. Amongst other things, it would do away with the fly-front, although the zip mechanism would still have to engage on one side or the other. As, physiologically, humans have two of everything visible at the sides and one of everything up the middle, we would merely be carrying-out what nature had intended by banning one-shoulder garments and the like. Consideration ought to be given to humane disposal of one-legged men and others similarly unbalanced. (It's strange but true that the average man has something like 1.9999 legs but the typical man has 2.0000; a good illustration of loose usage of statistical terms such as 'average'.)
As to driving on the right in the remains of the primitive world, it seems that this developed when one practical requirement usurped another. Originally, riding/driving on the left was the norm as this enabled effective use of a sword against oncoming foes, and at the same time facilitated mounting and riding with least danger or discomfort to riders or pedestrians. But then (to quote): 'In the late 1700s, however, teamsters in France and the United States began hauling farm products in big wagons pulled by several pairs of horses. These wagons had no driver’s seat; instead the driver sat on the left rear horse, so he could keep his right arm free to lash the team. Since he was sitting on the left, he naturally wanted everybody to pass on the left so he could look down and make sure he kept clear of the oncoming wagon’s wheels. Therefore he kept to the right side of the road.' Given the influence of Napolean across Europe and elsewhere and the desire of the Yanks to distinguish themselves from their British oppressors, it is hardly surprising that driving on the right gradually became the norm outside the UK and its major colonies - including much of Canada until post-WW2. Gibraltar is a notable exception, keeping right in harmony with Spain - a rule I must remember when I'm walking around there next Saturday - despite the 'British' bobbies, telephone boxes etc.