Connection between attention and forgetting

I have discussed attention (and mechanisms for focus of attention) in a good number of these blogs. I have also employed forgetting in Asa H, the simplest sort of passive forgetting being the deleting  of cases which seldom reoccur and/or have low utility. Attention and forgetting together have an influence on the performance of Asa H in any given working environment. Perhaps I need better algorithms for forgetting.