Everyone wants to be successful. Of course, your definition of success can and should be different -- because success should mean something different to each of us -- but still: We all want to succeed at whatever we choose to do. (Otherwise, why do it?)

But whenever I write about how success is often based on outworking other people -- both in terms of effort and in terms of hours spent -- I get indignant emails from readers.

"What about work-life balance?" some ask. "Work smarter, not harder," others say.

Yeah, well, no way. You can't have it both ways.

On the one hand, we celebrate people who have worked incredibly hard and achieved incredible success. They're icons.

Take successful entrepreneurs.

Bill Gates evidently never slept, never changed clothes, never did anything but code and maneuver and strategize. In an industry filled with incredibly smart people--where smart was and is commonplace--he rose to the top by also working incredibly hard.

Mark Cuban didn't take a vacation for seven years while he started his first company.

Elon Musk says, "You just have to put in 80- to 100-hour weeks every week. If other people are putting in 40-hour workweeks and you're putting in 100-hour workweeks, then, even if you're doing the same thing, you know that you will achieve in four months what it takes them a year to achieve."

In fact, the common theme of almost every tale of entrepreneurial success is a person who worked countless 18- to 24-hour days. Replace the names and their stories sound almost identical.

Even Tim Ferriss, the lord of the four-hour-workweek manor, stays incredibly busy with all his projects. (Of course, to Tim it doesn't feel like work.)

Or take successful people in other professions. Jeffrey Immelt, the CEO of GE, worked 100-hour weeks for 24 years. In a company filled with incredibly driven people -- where incredible drive is commonplace -- he rose to the top by also working incredibly hard. Tim Cook of Apple still wants to be first in, last out.

Or take sports. Forget practice and conditioning and everything else; Peyton Manning probably spent more time just watching film than the rest of us spend at work. In a sport filled with incredibly talented athletes -- where incredible athletic talent is commonplace --he'll be in the Hall of Fame because he also worked incredibly hard.

Hard work has clearly paid off for all of them. Yet somehow people think hard work won't work for them.

Maybe that's because of the whole "work smarter" thing?

Successful people already work smarter. They don't work mindlessly or inefficiently or ineffectively.

Where success is concerned, working smarter is a given. Extremely successful people work smarter and they work harder.

Their effort is heroic, their payoff is often legendary, and we celebrate them for it.

"Wait," you say. "Luck plays a big part in success. So does timing. So do a lot of other factors."

You're right.

But you can't control luck. You can't always control timing. You can't always control all those other factors.

What can you always control? How hard you work.

Again, everyone defines success differently, as well everyone should. (Before you go virtual-postal and say your personal definition of success has everything to do with balance and personal relationships and nothing to do with mastering the business world, read this. I'm totally with you.)

But if you happen to define success by traditional measures like professional achievement and fortune and fame, hard work is the great equalizer.

You may not be smarter than everyone else. You may not be as talented. You may not have the same great connections, the same great environment, or the same great education.

If you're on the downside of advantage, you may have none of those things.

But you can always rely on your courage, your effort, and your perseverance. You can always substitute effort for skill and experience, secure in the knowledge that, over time, incredible effort will absolutely breed skill and experience.

You can always, always, always work harder than everyone else.

Want to be different? Hard work can be your immediate difference.

Make hard work your favorite words, whether at work or at home or in your marriage or wherever your definition of success takes you.

That way you'll never have to look back and wonder what you might have accomplished if only you had tried harder.