I know that if I start my day with a plan to accomplish things, and immediately get started, I feel much more fulfilled and satisfied when I head back to bed that night. On the days that I slug around and put in half the effort I go to bed thinking "Well, that day was a waste of time." It feels a lot better to be determined and satisfied than sluggish and wasteful.
And I want to point out that it doesn't really matter what you set out to do for the day. I mean, if your goal is to watch 12 episodes of your favorite show, then you own it, accomplish it, and feel good knowing that you did exactly what you intended to do! But maybe tomorrow you should get started on that pile of laundry.
Feel free to share this with anyone who needs a reminder to stay determined.