Much has been written about entrepreneurship. But trying to develop academic theory on a subject that is anything but academic is difficult to the point of futile. While there are undoubtedly lessons that can be learnt and applied across different businesses and sectors, no two businesses and certainly no two entrepreneurs are alike, so self-help manuals have severe limitations.

Some things in life can only be learnt through experience – and entrepreneurship is one such thing. Having said that, let me tell you what I have learnt from building a business from scratch to £250m of annual revenues that might be of use to any entrepreneur. While the complexity of building a business cannot be distilled into any single or simple idea, I do think there is one question that encapsulates what it takes to become a successful entrepreneur. It’s a question that often confuses people with its simplicity: how badly do you want it?

The cold reality is that creating something from nothing is incredibly hard, as the failure rate of start-ups attests. It is only an immense, relentless, often maniacal passion and energy that make it work. You must want to be successful so badly, so deeply and so ferociously that you are willing to do whatever it takes. Those words are very easy to say but much harder to live by every day for years, especially when you may not be seeing results.

As an entrepreneur, this mindset becomes deeply embedded in you, and it is this more than intellect or academic excellence (helpful though they undoubtedly are) that sets the successful apart from the rest. Speaking from personal experience, sleepless nights, cancelled holidays and an almost constant state of paranoia and anxiety are all par for the course when building your business.

If you can’t deal with the intense emotional pressure, entrepreneurship isn’t for you – no matter how good an idea you may have. As all real entrepreneurs know (not the armchair variety who specialise in strategising but rarely have skin in the game), it’s so easy to get lost in the tidal wave of advice that comes your way when starting and growing a business.

Should you position yourself as a premium brand or mass market, focus on the wholesale channel or direct-to-consumer, prioritise domestic markets or think internationally from day one? While analysis is important and research is valuable, I see far more entrepreneurs make the mistake of not acting quickly enough than those I see move too quickly and not analyse enough.

It is well documented that the US has a very different attitude to entrepreneurship and risk-taking than the UK does. They are far more supportive of a move-fast-and-break-things or get-big-fast approach than us Brits, so it’s no accident that many of the world’s best and most dynamic companies are built in that market.

There is a motivational speaker in the US called Eric Thomas. His speaking style won’t be to everybody’s taste, but I would highly recommend checking him out on YouTube. He tells one story in particular about an elderly mentor wanting to teach an important life lesson to a young man in his charge.

Instead of taking the man to a classroom, he takes him out to the ocean and proceeds to hold the unsuspecting tutee’s head under the water until he is thrashing around furiously to be freed. After more than 45 seconds, the old mentor releases the young man and after a period of panic, once his breathing returns to normal, the old man calmly states, “Only when you want to succeed as badly as you want to breathe, will you be successful.”

While this story is clearly an extreme example and better left as an ancient parable rather than anything for the modern world, the core lesson it imparts is still a valid one. A burning, intense desire for success is a prerequisite as a founder.

In sport, we lionise great athletes for their work ethic and tunnel-vision commitment to their craft. We celebrate Michael Jordan or Tiger Woods for putting more hours into practice than their competitors.

For reasons unknown to me, we don’t seem to apply the same standard in the business world. Instead, we talk about maintaining work/life balance and avoiding burnout, criticising anyone who shows athlete-level commitment for championing “hustle culture”.

But just as athletes need to be willing to sacrifice more than their opponents in pursuit of victory, entrepreneurs must do the same, no matter how much society may tell them otherwise. The life of an entrepreneur is a truly great one – but it’s only for those who truly understand the costs that come with it and are willing to pay that price.

Tom Beahon is the co-founder and chief executive of the sportswear brand Castore