Drivers Wanted, must know how to drive on both sides of the road. . .

To calm my confusion I googled right side driving and what did I find ?. . . . Advice like. . . visitors are informed that UK drives on the (LHS), that's the left hand side of the road. In the interest of safety, YOU are advised to practise this in your "COUNTRY OF ORIGIN FOR A WEEK OR TWO BEFORE YOU VISIT" ya right! Exactly how would that work? Or how about the transition of a country from LHS to RHS, a governmental announcement, says that the change will happen in phases . . . where taxis and buses will first drive on the RHS with cars and trucks driving on the LHS until 90 days pass. Did they think that thru?