Everyone has different reasons for keeping lists. It could be for organizational purposes or for personal goals.
I found that if I don't keep a list (regardless of some of it doesn't get done or not.) things get a bit chaotic, appts get forgotten, phone calls are missed and that small window of time for myself that I would have otherwise had if I didn't miss one of the above things is gone.
Example of my list is as follows:
Double check on Mom's prescriptions
Put dinner on before I log into work.
So, how do you plan your day?