I think the trick is to try and fight through the excuses. Some days I just don't want to work out, and I tell myself excuse after excuse why I can't/shouldn't today. Then I fight through and just get it done, and am so glad at the end. I don't always win, and will skip a day or two, but then I make myself restart that week next Monday.
Having a workout partner to help keep you motivated also helps.
I am 6 weeks into my second normal round (first time was about 4 years ago and had great results, but got lazy afterward and didn't maintain). In 6 weeks I am down 23 pounds (from 188 to 165).
Best of luck!