There was a period in my life where I had a lot of things I wanted to do, but I never seemed to get anything done.

I would wake up in the morning, telling myself that today would be different. Today, I would be super-efficient. I would cross dozens of things off my to-do list.

I experimented with all sorts of productivity systems. Restructured my to-do list dozens of different ways, based on which self-help book I was reading at the time.

I had given up TV. I gave up reading for fun. I gave up everything that I thought was a distraction outside of my day job so that I could shut myself in the spare bedroom for a couple hours after dinner and make progress on my writing.

And yet, at the end of the day, I still felt like I had wasted my time.

I don’t remember who introduced me to the tool that saved me. It might have been yet another self-help book. Or it might have been my husband.  Or a blog post that I’ve since forgotten.

But here it is:

I know. It’s not a cool piece of software with flashing icons and reminders that guide me through a carefully-crafted schedule. Or an elaborate chart that gives me an up-to-date dashboard for every aspect of my life.

It’s a time log. A piece of paper and a pen, which I use to note the start and stop time for each task I do during the day.

It takes a second to notice the time, and a few more seconds to jot it down with a short note each time I switch tasks. I probably spend less than five minutes each day updating it.

There are no rules about what I do–the only rule is: whatever I do, I must record it on the time log.

But it’s been the difference between me not getting anything worthwhile done and me making significant progress on my big projects every work day.

There are a number of proven psychological reasons why a time log can skyrocket your productivity.

#1: It increases mindfulness, helping you to make better decisions.

I was in serious denial about how I was spending my time. I thought I was spending two hours writing every evening, when in reality, I was spending most of my “writing time” looking things up on the internet, sending “quick” replies to emails, and fussing with my story notes.

I was doing almost everything BUT writing during my writing time.

#2: It gives you an accurate record of how you’re using your time (and shows you exactly where you’re wasting it).

After two days of keeping a time log for my writing hours, I realized that I was never going to make any progress as long as I had email open. (For some of your, that will be Facebook or Twitter or your favorite chat program.)

I decided that I would spend 15 minutes sending emails before I started my writing session, to get that urge out of my system.

I also realized that I needed to ask my husband to only talk to me if it was an emergency. I was stopping at least once or twice in that two-hour period to have a conversation with him that would often last 15 minutes. That was 1/8th of my writing time gone.

#3: It puts a stop to multi-tasking, which is another word for “distracting myself from getting things done.”

Studies on multi-tasking have shown that every time you switch to a new task, it takes your brain time to adjust to the new task. And that people who focus on a series of tasks one-at-a-time finish those tasks much more quickly than people who try to complete multiple tasks simultaneously.

We all complain about feeling frazzled and overwhelmed, and we are doing it to ourselves by asking our brains to constantly switch from email to Facebook to television to face-to-face conversation to Twitter every few seconds.

When I stopped trying to multitask, my stress levels went down by about half almost immediately.

Because I had stopped asking my brain to the unnecessary extra work of shifting focus repeatedly in a short period of time.

Once I realized that I was wasting most of my mental energy just on adapting to the constant switching, I embraced pomodoros (timed intervals where you only work on one task at a time). And my productivity went through the roof.

#4: It helps me get a better handle on how long things really take, which has allowed me to be more realistic about what I can really do.

I spent a lot of my life feeling overwhelmed because I used to be incredibly optimistic about how quickly I could get things done. And as I said “yes” to more and more things, I found myself pulling all-nighters to keep all the commitments I’d made. Or worse, asking people for multiple extensions to allow me to catch up on deadlines I missed.

Now, as I continue to track my time, I can look back through my log notebook and see how long different types of projects really take. How many words I can really write in an hour. How many pages I can really edit in a day.

I’m not perfect. I still sometimes I bite off more than I can chew, and I fall behind on one project or another–especially if it’s a new challenge, something I’ve never attempted before. (I had a little bit of that with the plotting webinars last month, and am working extra hours to catch up there.)

But I’m getting better as I continue to log my time.

#5: It increases my sense of satisfaction with my day.

Psychological studies have shown that crossing things off a list doesn’t make you feel happier about what you’ve done–the opposite, in fact. It makes you feel like you’re behind and you’ve got to work through your list just to get back to ground zero (i.e. a blank to-do list).

Those same studies have shown that making a list of the things you’ve accomplished, however, significantly boosts how happy you feel about your day.

Let me repeat that, because it’s really important. The simple act of writing down what you did each day makes you happier.

I’ve told so many people about the incredible increases of productivity I’ve gotten from this simple tool.

And everyone is excited about it until they realize it isn’t some cool piece of tech. Then they get that look on their faces that tells me they’re not going to try it.

Because it seems too simple.

You’d think they’d be delighted. Just write everything you do down and you’ll be more productive. Add a time stamp as you chronicle your daily achievements, and time management becomes a piece of cake.

But instead, their reaction is often somewhere between disdain and disbelief.

There’s a psychological reason for that too–we tend to want the complexity of our solutions to match the perceived complexity of the problem.

In other words, if I live with a problem for years, and then I discover that something incredibly simple fixes it…I feel like an idiot for not seeing that solution when the problem first started.

So instead, we rationalize. We come up with all sorts of reasons why that simple solution won’t work before we try it, and that saves us from having to feel dumb for not having seen the solution sooner.

But here’s the thing. We’re not dumb. We’re just overwhelmed with everything that’s going on, and we don’t often have the luxury of sitting down and really thinking about our lives. Or we get so much advice that we don’t have time to evaluate, so we ignore it all and keep on doing things the way we always have. We miss the simple fixes as we run from one task to the other, constantly trying to catch our deadlines.

I’m not saying that you should be anal-retentive and chronicle every last minute of each day for the rest of your life.

It’s a great exercise to do for a week, though, to get a clearer picture of how you manage your time.

It’s also a fantastic tool for keeping yourself focused during your scheduled work time or writing time.

Just knowing that you’re going to be writing down the next thing you do makes it easier to choose a worthwhile task over a waste-of-time activity.

I only log the hours that I’ve set aside for working–the rest of my time is my time, to spend with loved ones, to do fun things.

So if you’re wondering why you seem to work for hours and get nothing done, or if you feel like your schedule is completely out of your control, please consider logging your time for a few days. It’s an eye-opening experience.

And once you’ve done it, I’d love to hear what you learned!