WE HAVE all made decisions we regret in life, but Chris Hill-Scott’s mistake might take the cake.

In 2008, Mr Hill-Scott and his friends Jon Reynolds and Ben Medlock co-founded a replacement predictive text keyboard app for phones and tablets known as SwiftKey.

Only two months into the venture, he was growing tired of the long hours and financial instability, so he decided to trade his shares to his friends. In exchange he got a bike, which no doubt seemed like sweet deal at the time.

But hindsight is a wonderful thing.

Just this week, the now-29-year-old watched as his former business partners became instant millionaires after Microsoft acquired the technology — which uses machine-learning to predict what users will type next — for a whopping $346 million.

Speaking to The Times following the sale, a spokeswoman for SwiftKey said there was no animosity between the Mr Hill-Scott and the two other co-founders.

“Chris was a friend of Jon’s from school and Ben was a friend from his university in Cambridge. Two months after forming the company, Chris decided to leave … Jon and Ben bought his shares. He left on good terms,” she said.

However, Mr Hill-Scott’s Twitter account hinted he might have been a little jaded about missing out on the $50 million each of his partners reportedly received from the sale.

He described his decision to walk as “the biggest mistake I ever made” before changing his privacy settings, reported Quartz.

Following the departure of Mr Hill-Scott, Mr Reynolds and Mr Medlock released the first version of SwiftKey for Android in July 2010.

Initially users were forced to pay $4 to use predictive keyboard app, however the company made the decision to change to a free download model in 2014.

The new model was monetised by offering users features such as different coloured themes and personalisation via in-app purchases.

Revenue was also supplemented from tech giants Samsung and BlackBerry, after making the app come as standard on their phones.

Used on 300 million devices worldwide, SwiftKey’s artificial intelligence and typing prediction technology is largely considered to be the best in the world.

Not only does the technology claim to know what a user will type next based on their unique writing style, but it can learn the slang terms, emojis and nicknames frequently entered by users.

As testament to the product’s success, the technology was recently built into the communication system of renowned astrophysicist Stephen Hawking to help him converse more easily.

At least Mr Hill-Scott has a flash bicycle, right?