I completely understand. My workouts have changed as I've grown older. But for awhile(many years ago) I did 50 sit-ups, 25 push-ups, and 50 leg-lifts every single day. If I was ready to go to bed and hadn't done them I made myself do them. That was the only way I knew that I would keep going.
Setting your goals ahead of time is a great way to keep to your plan.