Everyone makes mistakes. But some people make bigger, more public, mistakes than others.

Here are 5 legendary fails that have gone down in history, which can teach us some important lessons whether you’re a business leader, an event planner or aspiring entrepreneur.

Related: 7 Things only bad event planners ever say

1. Gerald Ratner – “we sell crap”

Think before you speak – this is a valuable piece of advice. One which Gerald Ratner no doubt wishes he’d adhered to back in 1991, when he wiped £500 million from the value of Ratners jewellers with one speech.

Ratner was speaking to an audience of 5,000 at an Institute of Directors conference when he revealed how his company – Britain’s largest high-street jeweller – was able to sell at such low prices: “it’s all crap”.

He added that his stores’ earrings were “cheaper than an M&S prawn sandwich but probably wouldn’t last as long”.

The poster boy for epic business fail, Ratner has still not lived this one down more than 20 years later – “Doing a Ratner” is shorthand for screwing up. Without a doubt, ‘crap-gate’ tops the list of easily avoidable business mistakes.

Lesson: Respect your customers and believe in your product

Related: Learning from your event mistakes to come back stronger

2. Clifford Stoll – “the internet will never catch on”

In 1995, US astronomer and author Clifford Stoll wrote an infamous article for Newsweek titled “The Internet? Bah!”

Stoll explained why the internet would never take off, why we would never shop online, consume media digitally or adopt computers in schools. Here are some highlights:

“Visionaries see a future of telecommuting workers, interactive libraries and multimedia classrooms. They speak of electronic town meetings and virtual communities. Commerce and business will shift from offices and malls to networks and modems. And the freedom of digital networks will make government more democratic. Baloney.”

It’s an important reminder that we can’t always be so sure what the future holds, and not to bet against the advances of technology.

Lesson: Don’t underestimate the power of new technology to disrupt the status quo

Related: 10 Event Technology Trends To Watch In 2015

3.  Ed Balls – #EdBallsDay

Celebrated on April 28, Ed Balls Day is growing in popularity every year. If you’re yet to take part in the festivities, let me fill you in. It all started four years ago when Shadow Chancellor Ed Balls accidentally became an internet phenomenon by tweeting his own name.

Balls was new to Twitter and didn’t fully understand how it worked, so when an aide suggested he search for an article on the network which mentioned him, he simply entered his name and hit ‘send’.

The Twittersphere reacted with delight, retweeting the message over 37,000 times and giving it more than 18,000 likes. The anniversary of the historic tweet is now celebrated across the internet. Even brands like Tesco, Pizza Hut and Virgin Trains have got in on the joke. At least Ed Balls himself has taken it all in good humour, retweeting his original tweet at 5.20pm every April 28.

Lesson: Understand the basics of social media before diving in

Related: 5 LinkedIn mistakes that make you look like an amateur

4. UK Publishing Industry – “Harry Potter is too long for a children’s book”

She may be one of the richest women in the world now, but J.K. Rowling’s literary genius went unnoticed by the majority of British publishers back in 1996 when she was trying to get signed.

The author’s agent sent the first Harry Potter manuscript to no less than 12 publishers before it was picked up by Bloomsbury. The main reason for its rejection was that, at 320 pages, it was deemed too long for children.

Finally, Rowling’s agent pulled in a personal favour and sent it Nigel Newton, Chairman of Bloomsbury Publishing. Newton gave the manuscript to his 8-year-old daughter to read and – at last – someone realised the brilliance contained within.

The series went on to sell more than 450 million copies worldwide, not to mention the films, theme parks, merchandise.

Lesson: Maintain your childish curiosity and don’t be afraid to challenge conventional wisdom

5. John Pluthero – “it’s going to be hell”

When John Pluthero took over as chief executive of troubled telecoms company Cable & Wireless UK in 2006 he didn’t mince his words.

Rather than take the traditional approach to motivating his new workforce he sent out a memo to staff which said: “Congratulations, we work for an underperforming business in a crappy industry and it’s going to be hell for the next 12 months.”

Pluthero, who made his name at the internet company Freeserve before running Energis, added: “If you are worried that it all sounds very hard, it’s time for you to step off the bus. This is no longer a place for the timid. ”

Did the tough talking work? Did it heck. Pluthero quit Cable and Wireless after less than 6 months when the company swung to a £433m half-year loss.

Lesson: When times are tough, teams need an inspiring leader not one that spreads doom and gloom

Related: 5 Tips to stay motivated during tough times

Conclusion

It can be easy to publicly fall flat on your face – and with the rise of social media, a single misstep can be globally amplified in minutes – so it pays to try and learn from others’ mistakes, meaning we can hopefully avoid making our own.

As the Russian expression goes: “The wise man learns from someone else’s mistakes, the smart man learns from his own, and the stupid one never learns.”

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