If you want to get better results from your fitness routine, measure your progress -- literally. When you need motivation for a goal, pick something related to the goal for which you can track statistics, like your body fat, your waist size or the distance you can comfortably run. Take measurements regularly and write them down, so you can quantify exactly how close you are to your goal. This technique has been shown to improve motivation, as it helps people believe in the reality of their accomplishments.
It is not silly at all to emphasize the importance of a positive mood to fitness. When you work out in a good mood, you will exercise harder, benefit more, and be able to go further. When you feel positive while you exercise, you focus on the good results instead of the negative obstacles on your road to fitness.