Why is it harder?

I find it so much harder to commit to losing weight when I am in pretty decent shape to begin with. Don't get me wrong there is definitely some extra pudge covering up those lovely strong muscles I would like to show off but the fact that I generally feel strong and firm under it somehow makes it harder for me than when I feel weak and lazy and out of shape. Does anyone else feel that way? Not that I want it any less, it's like my mind is tricked out of thinking I really NEED it. I am sure that makes no sense. Almost time for pilates class!!