David Allen has said in his book, Getting Things Done, that the edges have become blurry in knowledge work. Many of us work with information. At the end of the day, you have produced more focused, directed information for yourself or someone else. You are moving information around all day. You are receiving information.
In knowledge work, you can likely be twice as productive. It requires personal processes. What happens when you get something new? An email, memo, or verbal instruction? What system does it enter? Is your personal process consistent and predictive? Such a system would give you peace of mind as you work and more capacity to be ready for anything. For starts, try to minimize the number of places where you get stuff. Commit to one place. If you use Outlook, it may be your inbox. Email yourself tasks or reminders. Get an efax account and fax yourself paper documents that will come to your email. Minimize the number of collection points as a start. From there, the process begins. You can learn more at my resource page for how to keep a ZeroInbox here.