“Experience is what you get when you didn’t get what you wanted.” I first came across this quote when I was reading a book by the bond market investor Howard Marks, and it instantly resonated with me. As an entrepreneur, it’s all too easy to get carried away when things are going well, believing that will continue forever. Real value is created in the toughest times.

The question I’ve been asked more than any other is what makes entrepreneurs different. I’ve come up with a list of things it’s not: it’s not any intellectual superiority, though a level of commercial acumen is certainly helpful; it’s not the drive and determination they have, important though those qualities undoubtedly are; it’s not even the capacity to take and bear risks – most entrepreneurs I know dislike risk and attempt to control it rigorously.

It took me longer to realise what it was, but I believe the single factor that defines entrepreneurs is their ability to deal with setbacks. The normal human response is first to take it personally and then avoid any situation where it could happen again. While understandable, these responses only culminate in one destination – the comfort zone – and nothing worthwhile is ever achieved there.

The entrepreneurs’ response is to embrace the experience and then use it to learn how they can improve going forward. This enhances their chance of success more than almost anything else.

The idea that successful people are built differently to others is just not true. In my experience, the vast majority have simply learnt to deal with setbacks better than most and keep moving forward long after everyone else has given up.

Resilience is not a particularly fashionable characteristic, but it is an incredibly important one. Maintaining a consistent work ethic and positive energy during good times and bad is far more fundamental to our success than a game-changing moment of inspiration.

At Castore, we have also had to overcome plenty of setbacks. I lost count of the number of rejection letters we received from investors when we started the company, not to mention the factories that didn’t want to work with us, potential hires that didn’t share our vision or retailers that didn’t want to stock our products, alongside the people who simply enjoyed telling us we would fail. What none of them counted on was our ability to never give up and our desire to keep getting better every day.

This approach rarely manifests itself as a parting-of-the-ocean moment when everything changes forever, but in small incremental improvements that often take longer than you’d like. Pursuing your goal when you aren’t seeing the results you want is incredibly tough, but it is exactly this quality that separates successful entrepreneurs from everyone else.

Great businesses are built across many years, as are great business leaders. Roger Federer is a truly impressive tennis player, but his immense natural talent is hard for me to relate to. Andy Murray, meanwhile, possesses a huge amount of innate skill, but he has had to employ serious reserves of grit, determination and desire to constantly improve no matter what. That is truly inspirational.

The positive news is that grit and resilience are skills anyone can learn. They’re not easy to acquire, but then nothing worth having in life is. While few of us have the fortune of being born with world-class natural abilities, all of us can learn how to react constructively when life gets tough.

Positive energy is infectious and, in my experience, the world rewards those who keep going. The world of sport may be unforgiving for those without a natural gift, but the world of business embraces such people with open arms.

Never see setbacks as terminal, don’t judge yourself by others’ expectations, be humble and never stop improving. Do all these things for long enough and there’s no limit on what you can achieve. Tough times don’t last, but tough people do.

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