Then, during the French Revolution, they wanted to change as many things as possible (for the sake of change), and switched to riding or driving on the right. That spread to other countries but England rejected any innovations coming from the French Revolution (although they did eventually go to the metric system).
I'm not sure if that is correct or just an urban legend.
I’m a righty, but when I got my first computer in 1996, I purposefully trained myself to use my left hand on the mouse, which gave me easier access to the enter and arrow keys. Drives my kids crazy!