How is entrepreneurship like skydiving? As they say, the hardest part of skydiving is jumping out of the airplane. I think entrepreneurship is the same way.

I believe that the key to success in life is overcoming your fears and eliminating the excuses that keep you in your comfort zone. Action almost always brings more fulfillment than the status quo. “Ready Fire Aim” is an expression of that ethos. I also believe it’s very applicable to entrepreneurs thinking of starting a company – the starting is often the hardest part.

Think of all the “armchair entrepreneurs” in the world – everyone has an idea. And yet nobody executes. There always seems to be a reason to delay actually starting an entrepreneurial venture. I don’t have enough startup capital. I need to refine my idea a little more. I should save some more money first. I need to finish college first. I don’t know if anyone will use it. There are one thousand and one excuses for putting off starting until tomorrow.

So why do we do this to ourselves? What is it about human nature that makes us manufacture endless justifications for inaction? I want to mention two authors who’ve written about it specifically, one classic and one contemporary.

Sigmund Freud called these nagging doubts the Death Drive, or Thanatos – the destructive force inside human nature that rises whenever we consider a tough, long-term course of action that might do good for ourselves or others. The opposite of Eros (the drive for life), Thanatos is the natural drive in all of us to give in to the status quo and seek a state of calm, non-action, and death.

Stephen Pressfield (author of “Legend of Bagger Vance” and “Gates of Fire”) has a wonderful contemporary description of Thanatos. Pressfield calls it “Resistance” in his new book “The War of Art” and defines it this way:

Have you ever bought a treadmill and let it gather dust in the attic? Ever quit a diet, a course of yoga, a meditation practice? Have you ever wanted to be a mother, a doctor, an advocate for the weak and helpless; to run for office, crusade for the planet, campaign for world peace, or to preserve the environment? Late at night have you experienced a vision of the person you might become, the work you could accomplish, the realized being you were meant to be? Are you a writer who doesn’t write, a painter who doesn’t paint, an entrepreneur who never starts a venture? Then you know what Resistance is. Look in your own heart. Right now a small voice is piping up, telling you as it has ten thousand times, the calling that is yours and yours alone. You know it. No one has to tell you. And you’re no closer to taking action on it than you were yesterday or will be tomorrow. You think Resistance isn’t real? Resistance will bury you.

So how do we overcome Resistance and accomplish our dreams? To put it simply, “JFDI” (think Nike).

People and ideas have inertia. That which is at rest tends to remain at rest, that which is in motion tends to remain in motion. I think the key to starting anything is to actually start. Take the tiniest first step. Get off the couch. Put out an ad for a web designer on Elance. Draw out a mockup in pencil. Make that first phone call. After you’ve started, I think you’ll find the second step comes much more easily. Make that inertia work for you.

The truth is that the only way someday turns into today is by getting off your butt and starting. Starting makes things real. Starting builds momentum. Starting gets you excited. Starting eliminates all your excuses and all the reasons you’ve invented in your head to rationalize your inability to overcome your inertia. Starting makes you an entrepreneur.

I also want to point out that in order to succeed with a “JFDI” philosophy, you must also excel at correcting course along the way – what some call pivoting. It is the final and most important term in the phrase “Ready Fire Aim”. Too often we all forget to aim. Most successful business are not perfect incarnations of the founder’s first business plan, they require a lot of adaptation along the way. Very rarely is it purely a brilliant concept that makes a startup successful. Success is a sustained, long term drive, and that’s far rarer than a good idea.

Twitter is a perfect example – it started as a side project inside a company called Odeo (also founded by the Twitter guys). They soon noticed that Twitter was far more popular than Odeo’s main product offering, a podcasting web app. They scrapped the Odeo idea entirely and focused all their time on Twitter, which now has over 150 million users. Good aim.

In summary, success is action plus agility. Get the ball rolling, put inertia to work for you, and correct course along the way. Jump out of the airplane. I’d like to leave you with a quote from Machiavelli that I have printed out and hanging above my desk. Hopefully it helps remind you to go out there and JFDI.