Effective executives know that they have to get many things done effectively. Therefore, they concentrate. And the first rule for the concentration of executive efforts is to slough off the past that has ceased to be productive. The first class resources, especially those scarce resources of human strength, are immediately pulled out and put to work on the opportunities of tomorrow.
If leaders are unable to slough off yesterday, to abandon yesterday, they simply will not be able to create tomorrow.
Peter Drucker – The Effective Executive