If the adults have high walls, the children learn that, too. If parents pay too little attention to children they build crusty, jagged walls. In some cases the walls last until adulthood. As some people grow, they may learn to put windows or doors in their walls. Some learn to put them up and down at will.
Some walls never come down for any reason.
You can put your walls down at any time in your life as you learn the tools to deal with emotions. The walls keep out hurt, keep in anger, but they also keep out love and caring. Love comes in many forms. Love is as vital to our well-being as air and water. Love heals wounds, keeps us well, and teaches us new skills.