Although it may seem like a paradox, forgetting is an important part of remembering. Your ability to block unimportant memories enable you to remember the important things by reducing the demands on your brain. In a study, people who were able to tune out irrelevant words in a word memorization test were able to recall the relevant words more accurately. The brain plays favorites with memories, snubbing some in order to better remember others. Scientists studying people with super-efficient memories say that their ability often develops at the expense of emotional intelligence and abstract thinking. In her memoir, The Woman Who Can't Forget, Jill Price explains that her near-perfect memory is more of a curse than a blessing. Her memories are so vivid and complete that "it is as though I'm actually reliving through them again." They force her to relive every sad, humiliating, and painful experience from her childhood, chaining her to the past. "It's hard to grow up," she wrote, "when you're walking beside yourself." * Reference New York Times
I can understand how Jill Price feels. I have very clear memories going back to my childhood, including all the embarrassing, shameful and bad things that ever have happened in my life. These often pop into my head and I feel them all over again unless I can force myself to stop thinking about something I said or did several decades ago. As part of developing a more positive attitude, I have deliberately tried to block out bad memories, to live more in the present and to create better memories for my future. This has worked to some extent, but not as much as I would have liked. It still takes me some effort to stop any memory I'm reliving in my mind. I have to order myself to "stop remembering that" and I imagine taking a physical hold of the memory and throwing it away. It is only effective in the short term as those memories never do go away completely and can reappear at any time. It's like having a rogue MP3 player that keeps bringing up tracks I would prefer to delete completely, but I'm unable to stop them replaying randomly. If there is an effective mind technique for removing specific memories, I would be happy to give it a try.
I can't say how effective what I do when I have those very painful memories come up can be for some one else but I start to hum a song, the sound of the humming is louder than the thoughts in my head so that I don't hear the thoughts. I will start to hum as soon as I realize I am having a thought that is going to cause me to be depressed for days or is bring up pain that I don't want. I may also start to dance around to get my body moving along with my mind. The good about the thoughts is they don't last for long.