Aren't door knobs supposed to be on the right hand side of entry doors?

I'm pretty sure it depends on which side of the door you're facing. By default, it appears on the left from outside the room, but on the right when viewed from inside the room. Like others said, you can flip the doors around, but this also makes the doors open outside the room not inside it. But with doors, it's important that they allow for easy traffic, so the way they open depends on the layout of the house. Also, for fire safety and easy evacuation, doors in public places are supposed to open to the outside.