But you can learn. What's happening here is that you are establishing boundaries. I will not let other people affect what goes on inside my boundaries. When other people engage in obnoxious behavior on the net, they are attempting to crash over your boundaries, and affect what's going on inside you. You aren't going to affect what's inside of me.
Boundaries are different from walls.
When we put up a wall, we are hiding what's inside of us. We are taking the position that if people don't know about something inside of us, they can't use it to hurt us. The problem with walls is that whatever is behind the wall is a secret. Yet we form or join support or discussion groups such as this one because we need to take these issues out into the open and talk about them. But when walls are our only protection, it's hard to tear them down and leave ourselves exposed.