There are many similarities between the biology of memory and the biology of pain, although that level of detail is not for here. We know that some important memories can be maintained throughout our lives, and some memories are kept for a shorter time. We are able to ‘recall’ memories, for example if I was asked my mothers name or my address then I can ‘remember’ or ‘recall’ that information. A simple cue (the question asked) diverts my attention to the question, my brain then makes sense of it and goes and finds the answer.
It is easy to see that if I am frequently thinking about my pain, especially if I am very worried or anxious about it then I am going to be making ‘memories’ of that pain. Committing anything to memory involves interest, attention, repetition and practice, and when you live with pain it is quite likely that you will be doing this. If you then add in strong emotions, such as fear, anxiety, sadness and anger then this makes it even more likely you will be laying down pain memories. In evolutionary terms it makes sense that anything that is threatening to us is remembered so that we make sure we avoid it in the future.