In addition to the (very, VERY real) forgetfulness issue, which a lot of people here have already covered, I personally find to-do lists a useful analytical tool. If something's been on my list for multiple days without getting done, why is that? Is the task not actually worth doing? Is there's something else that has to be done first in order to proceed? Do I have some sort of mental block against finishing it? Thinking about these things helps me cut the cruft and get the important stuff done. I can't imagine doing this as a purely mental activity, particularly in a cubicle.* Even if I were working in a monastery, using lists is faster and more accurate. The tool itself isn't evil; it's just people's relationship to it that's messed up. * Yeah, yeah, cubes are evil. But you can't expect people working in them to abandon all attempts to stay productive.