This is summary of a great post by Aytekin Tank: "Why high-performers don’t use to-do lists". I write it here again because :

1. I could bookmark the article. However, once bookmarked I doubt I will read and remember it later.
2. Writing a summary of an article helps me memorize and understand the most important part of the article.
3. Medium is quite heavy to access, so I put it here for faster access and for my archive.

Problems With To-Do List

To-do list is used to write down stuff that must be done within a time period. It's easy to do, just write things that must be done, do it, then cross it off from the list. However, there are some problems with to-do list :

• We as human are terrible at estimating how long tasks take.

  With to-do lists, we optimistically assume that most of the day's tasks will take less time than what they'll actually take. This causes the to-do list to "roll" into tomorrow.

• To-do lists are never quite done (some almost always "roll" into tomorrow).

  Once we finished a task in the to-do list, we will realize that the task wil give birth to a new set of tasks. These new tasks will end up on the bottom of our to-do list, which make it seems our work is never done. At the end of the day, these half-completed to-do list will hinder us from feeling a sense of completion with our day and our work.

• To-do lists allow us to avoid the important.

  To-do lists cause us to be overly proactive in our thinking. Which, in turn, causes us to put a greater emphasis on tasks that  (in the broader scheme of things)  aren't that important.

The Solution

Instead of writing down dozens of tasks that we need to get done each day, choose one that MUST get done and will deliver the most impact. If you don't know which task is the most impactful, just remember: it’s usually the thing you least want to do. Once finished, you can always go back to executing other low-priority or other operational tasks.

Example

Suppose we have a to-do list that belongs to Jim, a sales professional that works for a technology startup :

1. Get email inbox to zero.
2. Catch up on Slack messages.
3. Follow-up with Paul about lunch tomorrow.
4. Meet with the marketing team for "brainstorming" session.
5. Stop by the grocery.
6. Make '50' cold calls to potential leads.
7. Do a couple loads of laundry.
8. Clean the house.

While cleaning the house, doing the laundry, etc. might be nice, they aren't going to create the most impact for the day. However, if you’re a sales professional like Jim (where you get paid to make sales) you better make sure you're working on your 50 cold calls for the day.