This may not be especially helpful at the 3-week mark, but it can be good motivation to look back on your progress periodically. If body composition is part of your goal, take pictures periodically, and do "before and now" comparisons (you don't have to show anyone else; this is strictly for your own benefit). Do something that used to test your limits and notice that it feels easy now. Keep a log of little aches and pains, and review it to see how they've quietly fixed themselves.

Fitness can feel Sisyphean at times. Zooming out a little not only lets you feel more accomplished, it can get you excited for the future.

Unfortunately, I'm not sure this technique generalizes well to non-fitness endeavors.