I started out my career as a teacher in Japan. Then I became an entrepreneur. Today, I’m a productivity consultant.

Over the past 30 years, I’ve worked with CEOs, executives, doctors, teachers, athletes, kids, and even a Supreme Court judge. Having worked with such an array of people in different walks of life was a real eye-opener. What I learned is that we have a lot more in common that we realize.

When it comes to productivity, too often we’re our own worst enemies. We love to tell ourselves lies that hold us back from achieving our true potential.

The following are the ten most common I’ve been told over and over again.

1. I’ll do it later

Sure, sure. I’ve been guilty of this one, just ask my wife. I’m sure many of you can relate. If we can do it now, then do it. It’s essentially the concept of Brian Tracy’s bestselling book, “Eat That Frog” which talks about tackling the thing you like least, first. Don’t put off what you can do now.

2. I work better at night

Nice try. The truth is most of us aren’t as effective at night. The daily grind takes a mental toll on all of us. When we head home for the day, all most of us want to do is put our feet up in front of the TV and enjoy our favorite show. Work? Forget it. And word to the wise, night time is when we’re most susceptible to persuasion, so be careful.

3. That doesn’t matter

It all matters. Never overlook the small things. Every big thing is simply made up of lots of little things. In James Clear’s bestselling book, “Atomic Habits,” he talks about managing the little things; the big things take care of themselves.

4. It doesn’t work

I once heard someone say that the average amount of times people try something is 0.6 times. In other words, most people talk themselves out of even trying it. They believe it won’t work for them, so why even bother. Not everything successful people share will work for us. That being said, experience has shown a good deal of them will.

5. I only need five hours sleep

For now, maybe. But the human body needs rest. Navy Seals and unique individuals may be able to perform at peak levels despite only sleeping five hours. Chances are likely that’s not us. To operate at peak levels, the human body requires seven to eight hours of rest each night.

6. I’ll skip today and double it up tomorrow

Sounds good, but deep down, most of us know that we really have no intention of actually doing that. We just want an excuse not to do it.

7. I don’t like to be tied down

Those who don’t work from a calendar tend to say that it stresses them out. The problem is that not working from a schedule is recipe for disaster, especially in our age of information overload. Use a calendar.

8. I worked hard so I did a good job

Good results usually come from hard work, but the two are part and parcel. A lot of people believe that they worked hard, therefore they deserve to be paid for their work. Unfortunately, companies aren’t really paying you for the work you do, but the results you bring. It’s possible for two people to work the same amount of time and end up with completely different results. Work hard, yes indeed. But remember, it’s the results, not the time, that really counts.

9. I’m good at multitasking

Wrong! Multitasking is merely jumping from one task to another without actually focusing in on any of them. Thinking and analyzing something takes thought. The bigger the problem or issue, the more thinking and focus it needs. Darren Hardy, one of the top productivity experts in the world, lives by what something he calls “a jam session.” Ninety minutes devoted to one single topic. That single-minded focus is something the most successful people all have in common.

10. Perfection is the goal

We should all aim for perfection. However, the goal is not perfection. Apple products are considered some of the best around, but even they are constantly updating things. The goal should always be good enough. You can’t bat 1.00. In fact, a mere 0.3 batting average for a professional baseball player will earn him millions of dollars. In business, we must learn to delegate, even if the finished product isn’t quite what we want. If it’s 80% as good, that’s good enough.

Originally published on Business Insider.

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