Phychologist David Rubin hasdefriend something that he calls'memory bump. This refers to the idea that middle-age and older adults remember most strongly things that happend between the age of 10 and 30. This group is significantly differant form adults in ther early twenties, when important memories change constantly. In his study Rubin asked college students to tell him their most importani memories. When asked the same question six nouths later only 12 % of the college students repeated the same story. When we are so yong, we are still writing our own life story and there are often many major changes, such as our first job, marriage, and children. As a result, the telative importantce of events in our lives is aways changing.