Absolutely necessary, in my opinion. Although I would prefer to have ended things on a note of friendship, it wasn't possible because my ex has zero boundaries, no common sense, and an inability to understand how his actions affect others. Which is interesting because this was something he often projects onto other people, including me. Things he said and did after our split are mind-boggling, unless viewed through the myopic lense of narcissism. He views everyone as a tool to satisfy his needs, never truly offering himself in any capacity. And he thinks this is perfectly okay. It's not, if you want to be a decent human. I had hoped he would grow and change after our split, but he is very much still a work in progress. As are we all. But to protect myself, I had to go no contact for over five years. In the past year, in preparation for our son's wedding, there has been some contact. I just have to keep my boundaries and maintain some distance.