life underwater

What if everyone lived under water? Where would people live? What games would children play? What would school be like? If everyone lived underwater there would have to be something wrong with earth and land. Something that made us decide to live under water. Like what if the world was taken over by zombies or something dangerous. If people lived underwater children would play the same as they would now but in a more boring way because you can't go anywhere or do anything.I would think living under water would probably mean living in a building under water kind of like a closed submarine. Kids would still grow up like regular kids but except with advance technology. I would say this because in order to make a building under water you need advanced technology. School would be held in classrooms but kids would mainly study about technology and sciences. I would hate to live under water because I would feel trapped.