For a long time, I resisted to-do lists. I wanted the flexibility. I felt that if I kept a list, it would tie me down to a particular set of tasks. Gradually, though, I came around. The busier my work life became, the more crucial it was to have some sort of running agenda on hand. Before long, I even started adding some of those items onto my weekly calendar. In other words, I’d reluctantly become a planner.

Looking back, it shouldn’t have been so difficult. In fact, there are at least three psychological benefits to the simple act of drawing up a list of top-priority tasks–whether or not you actually accomplish them.

Keeping a list of tasks you need to perform is like taking notes when you’re reading a book or listening to a lecture. When you take notes, you need to filter external information, summarize it in your head, and then write it down. Many studies have shown that note taking helps us distill the information we hear and remember it better than we would if we’d just heard or read it.

Your brain decides which pieces of information to hang onto for later, partly as a result of how much work you do to them up front.

Writing a to-do list is a similar mental experience. Even if you first spend some time thinking about the tasks you have to do, the act of drawing up a list and prioritizing the items on it forces you to do a little extra work.

This matters. Your brain decides which pieces of information to hang onto for later, partly as a result of how much work you do to them up front–so the more you mentally manipulate a piece of information, the better you’ll remember it. That’s why it’s sometimes surprisingly easy to remember what’s on your to-do list even when you aren’t looking at it.

For most people, the challenge at work isn’t keeping busy hour by hour or day to day, it’s making sure we get the big-picture projects done that make work fulfilling. These are often broad, abstract goals that you hope to achieve over a period of weeks or months. The problem, though, is that they’re hard to achieve without breaking them into a coherent set of concrete actions you can take on a daily, weekly, and monthly basis.

Suppose you’re trying to write a book. You can’t do that without taking the time to do research first, then put in the hours writing, and finally spending time editing what you’ve written. All that takes time, and keeping an agenda of all the little “sub-goals” that will take you toward the larger, more abstract one can help you actually get you to a finished manuscript you’re proud of.