This is especially true with regard to unstructured content, most of which is duplicate information or unnecessary (think of all the junk and transitory email).
Spam might show up in my inbox a few times each week, while I need to remember to check several layers of junk mail filters for false positives legitimate email marked as spam by an aggressive filter.
We ran this story about conquering your email inbox, which recommends a system of prioritizing urgent items, dealing with short requests quickly, deleting junk and putting less pressing matters on a to-do list.