Procrastination vs. System
Another wedding was coming up (boy, there have been a lot of them this year). When I checked my suit to be sure it was clean, the pants were missing. A call the next day to the cleaner verified that they were still there.
Several months ago, I had a nagging feeling something needed to be picked up from the cleaners, so I put an item on my to-do list: phone cleaners. Months later, I still hadn't made a simple phone call.
My task "phone cleaners" was vague and thus not compelling. If I had written down "pick up pants from cleaners" when I dropped them off, the item would have been focused and actionable. Better if I set it with a deadline. Better yet if I set a lead time (start date), so I wouldn't see the task until it was time to act on it.
Tasks in a to-do system must be specifically phrased, with proper metadata, to induce action.
Without any system, I remembered what I needed to do, in adequate time.
(Counterargument: If I hadn't checked my suit a week in advance of the wedding, there wouldn't have been enough time.)
A task system should contain tasks that are non-routine, or otherwise non-memorable. It should not contain items that will come to your attention anyway (a full trash can is its own reminder).