Driving on the Left

In Thailand cars drive on the left side of the road. This was a bit confusing at the beginning because we would try to get into the passenger seat on the wrong side of taxis, or freak out when the taxi would turn onto the wrong side of the street, or look the wrong way when trying to cross the street. But then what is weird is that with the skywalks or entrances to the metro, they have arrows telling people to walk on the right side. Why the confusion?