Want to Be Successful? Focus on One Business. The latest myth is that entrepreneurs should start lots of businesses. Nonsense. In business as in life, less is more and more is never better.

Every time I turn around there's another loony fad making the rounds in entrepreneurial circles. I suppose that's the inevitable result of our insatiable appetite for online content. Truth, logic, and just plain common sense take a backseat to hype. If it sounds good, we click, post, tweet … rinse and repeat.

The latest fairy tale is that real entrepreneurs start lots of businesses. If you only start one company, you're limiting your potential. The more businesses you create the better, the more knowledgeable, influential, financially secure, and successful you'll become. And so on.

I understand someone actually launched one business a week for an entire year. Just between you and me, that sounds more than a little obsessive. Maybe it's cool for getting into the Guinness Book of World Records, but for serious entrepreneurs, not so much.

This is all so wrong I'm not sure where to start. Actually, let's start there. Since when is starting anything an accomplishment?

I don't care if it's a project, a race, a family, a foundation, or a business. Starting anything is relatively easy. It has little value. It's finishing that matters. Growing. Accomplishing. Achieving. Results. In a business, that means delivering value to customers, employees, and shareholders.

On Charlie Rose, Apple CEO Tim Cook explained that one of the core principles Steve Jobs instilled in the company is the need to stay focused on doing only what you do best. "It's easy to add … it's hard to stay focused," he said. "And so the hardest decisions we make are all the things not to work on."

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Indeed, Jobs once told Fortune, "People think focus means saying 'yes' to the thing you've got to focus on. But that's not what it means at all. It means saying 'no' to the hundred other good ideas that there are. You have to pick carefully."

In a recent Fast Company interview, Cook said, "There's this thing in technology, almost a disease, where the definition of success is making the most. How many clicks did you get, how many active users do you have, how many units did you sell? Steve never got carried away with that. He focused on making the best."

When it comes to anything important in life, more is never better. Better is better. And best is even better than that. Less is more. That's just common sense. In terms of everything that matters – love, passion, focus, attention – the more things you have, the thinner you're spread and the less you'll come to value them.

That goes for anything, from careers and businesses to loved ones and life itself.

Think about it. The best thing about life is that you only have one. That's where the richness, wisdom, and fulfillment come from. Imagine how superficial life would be if you started it over from scratch every few months or had to jump around between lives. That's not better. That's a nightmare.

Businesses and careers are no different. Picasso painted. Henry Ford made cars. Einstein was obsessed with light. They excelled at what they did because they focused their passion and attention on one thing at a time. Bill Gates had Microsoft and now the Gates Foundation. Mark Zuckerberg has Facebook. Same thing.

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The vast majority of successful entrepreneurs start one, maybe two companies. Sometimes they start more because it takes a few to get it right. They don't generally do more than one at the same time, however, but in succession.

And perhaps the most successful companies are one-trick-ponies: Intel microprocessors, Cisco routers, Starbucks espresso cafes, Whole Foods markets, Coca-Cola, and so on. In any case, they focus.

Granted, there are exceptions, namely diversified holding companies. But Warren Buffett spent two decades cutting his teeth in the investment business before founding Berkshire Hathaway. And Richard Branson focused Virgin solely on music for 13 years before venturing into airlines.

Elon Musk runs two companies – Tesla and SpaceX – and that occupies all his time to the point where he may have actually lost his family as a result. I guess that's his choice but it doesn't sound like a very good tradeoff to me.

Look, there simply is no truth or logic to this more is better nonsense when it comes to entrepreneurs and businesses. And I have to say, the vast majority of self-proclaimed serial entrepreneurs I've come across are posers trying to pump up their personal brands. They don't actually appear to be adept at anything. Don't drink their brand of Kool-Aid.

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