Someone recently asked me what the hardest part was about running a startup company.

I hardly knew where to begin. To say that building a startup is hard is like saying Mt. Everest is a difficult hike. Hard doesn't begin to describe it.

And yet the startup journey is also rewarding in ways that are equally indescribable.

The belief that an idea can change the world for the better is a powerful motivator, and witnessing the fruition of that idea? There is no paycheck that can come close to being as rewarding as that - figuratively and often literally.

I don't know if it is actually possible to choose one aspect over another as the most difficult part of building a startup, because it is the culmination of navigating through all of them without succumbing to any of them that moves a company forward.

But I do know that one of the most dangerous aspects of running a startup is losing the battle of the mind. It takes a significant amount of mental fortitude to conquer the inner battles that derail focus and positive energy.

The truth is that launching a startup is relatively easy.

Anyone who has participated in a weekend startup event has witnessed a multitude of ideas developed into a pitch deck ready for presentations to investors in a matter of hours.

But a pretty pitch deck does not a startup make.

When reality hits, and barriers crop up, the true challenges of a startup are just getting started.

It isn't just about vetting an idea for its business case. It is about finding the right team with the right mix of skills who are willing to work for little or no pay, who will carry the load of their own responsibilities without needing constant supervision.

It is about finding the sweet spot between the time and cost of getting an idea to market and the risk of running out of energy, commitment or money.

It is about tweaking an idea as many times as it takes to get it right without getting distracted into chasing every shiny new thing or reacting to the competition.

It's about learning new skills and taking on new roles that are terrifying but necessary, and doing so with a good enough attitude that it doesn't become a burden to the rest of the team.

It is about navigating the legal system to protect intellectual property and negotiate enforceable, fair agreements with partners, investors, customers and employees - that protect for the time being and for the future without strangling camaraderie or good will.

It is about fighting the hubris that success can bring, about fighting the death knell of inertia that failure can create and about making peace with the fact that the path of a startup is in falling forward through mistakes and miscalculations without allowing any one of those to become fatal.

And, mostly, it is about learning to function in a state of incessant worry - not only for yourself but also your team, investors, and customers - and not allowing the unrelenting weight of worry to dampen the ability to celebrate in good times and without becoming paralyzed when things are bad.

But the beauty of it all is that the when founders navigate these difficult waters of entrepreneurship without sinking, the rewards can be significant - financially but also personally.

When a team has learned how to fight and forgive and move forward, the loyalty and trust of the relationships forged in a startup can last a lifetime.

And when the inward battle of the mind is conquered, the confidence and courage that result from surviving the myriad challenges of a startup can lead to taking bigger steps with bolder ideas ... and deciding to start the journey all over again.