Wanting to forget something painful is understandable. On closer inspection though, it is another form of resistance. Resistance doesn't work in the long run, as a recent article from goodtherapy.org says "Many individuals who have survived a traumatic life event wish to simply forget about the experience, hoping that forgetting will be synonymous with overcoming. However, it is not possible to erase pivotal life experiences or to truly forget about them. The human mind and body remember and clamor for healing". My colleague Puja Kanth Alfred has written a great article on the need to forget or disown our stories by rewriting our memories.
I sometimes wonder whether the need to forget or disown our stories is stronger in others rather than in ourselves. Let's be honest, the pressure in society to be "positive" and "move on" is strong, even if that sense of positivity is feigned or forced. We therefore receive a lot of societal support in disowning, pretending, forgetting, dissociating, distracting and avoiding. It takes a huge amount of courage to face our pain and sometimes we can feel very alone in doing so.
Our need to forget can also ensure our survival in many cases, but again this sense of survival is short term. Surviving only gets us so far until the cracks start to show. Sooner or later, we need to address and heal our pain. What usually happens is physical and psychological symptoms worsen so they get our attention. We can see this in various different ways, I prefer to see these symptoms as a way of making us take our pain seriously. Serious enough so that we do something about it so it doesn't hurt so much, or at all.