Making a list of items to do can be very helpful, but we consistently underestimate the amount of time it will take to do something. So frequently plans made in the morning may not be fully completed because each task is pushed back to later in the day or deferred (put off) until another day.
Examples:
A man creates a list of things to do that day, including picking up food for dinner, getting his brakes fixed, taking his daughter to the doctor, filling out forms for school enrollment, and talking with his social worker about renewing his benefits. Everything takes longer than expected. So he misses his renewal, and his benefits expire.
A woman has a to-do list and changing her work health insurance during open enrollment is always on the list. But work is busy, and she never gets through the daily list, so she misses the window to enroll.