I think this happens to everyone...you can always push yourself a little harder in anything you do. I find myself going through the motions sometimes also and when I get my intensity back its amazing to see how you can break through lifts.

Sometimes when I get home and just can't find the motivation to go workout I pop in Pumping Iron and crank it. See Louie's dad yell at him just gets me motivated for some reason. NO MOE DAD, NO MOE!