Joanna Wong had been stuck in the same corporate job for years, becoming more and more disillusioned, when she decided one day that things had to change. "I was frustrated, I think, working in a large organization," said Wong. "I wanted to be able to make a bigger impact." So, she quit her 9-to-5 job as a womenswear buyer in Australia, and set out to find what she hoped would be a more fulfilling path as an entrepreneur. "The fashion industry wasn't being inclusive enough and didn't cater to plus-sized women ... I felt like I could enter entrepreneurship by solving a real problem for real women," continued Wong, founder and CEO of All Woman Co. Wong is not alone in her vision. Indeed, almost half (49 percent) of U.S. millennials say they'd like to start their own business, according to a study by America's SBDC (small business development center). Only it's easier said than done: Estimates suggest anywhere from 50 to 90 percent of new start-ups fail within the first few years. So, just what is it that sets apart the successful few, and how do you know if you've got what it takes to follow their lead? CNBC Make It spoke to three entrepreneurs — each with different stories but all of whom quit employee life to pursue the entrepreneurial dream — and found three key things united them all.

The dream

As cheesy as it may sound, first off, they all had a dream. It's a line often espoused by top visionaries like Elon Musk and Bill Gates, but it's also applicable to early-stage start-ups, the founders explained. "There was a problem that needed to be solved," said Wong, who launched her womenswear brand to fill what she saw as a gap in the market for larger women.

Joanna Wong, founder and CEO of All Woman Co., speaks at the demo day of start-up generator Antler in Singapore on January, 9. 2019. CNBC

For Guillaume Castagne, the motivation was quite different, but it was born out of a similar passion. Having worked as a management consultant in Paris for years, he dreamed of getting back to a more inspiring work environment like the one he experienced as an intern at Southeast Asian start-up, Lazada. "I witnessed the passion of the founders, the excitement of the employee to build a company from scratch, and I felt really in my element," he said of the e-commerce business. So, along with two fellow co-founders, he set up Cove Living, a "ready-to-move in" platform designed to simplify property rentals. Xinyan Fang, meanwhile, had entrepreneurship in her blood. Born to a father who also started his own business, she grew up watching him "pursue his dream" and wanted to follow in his footsteps. "I would say I've always wanted to be an entrepreneur," said Fang, who is founder and CEO of YoRipe, a grocery app for Southeast Asia.

The catalyst

Next, there was a catalyst that caused them to turn that dream into a reality. Fang, who worked in the hospitality industry before completing her MBA in Singapore, said that moment occurred for her while she was traveling. "I think the turning point was when I was in Israel," said Fang. "Someone told me the only way to fail is to stop trying. And, that moment, I knew I was ready."

Guillaume Castagne, co-founder and CEO of Cove Living. CNBC

Castagne, on the other hand, experimented with a number of entrepreneurial projects to build confidence before ultimately focusing on Cove Living. "I started a company called Vaniday, which is a beauty marketplace in the region (Southeast Asia), and that gave me a lot of confidence to start something on my own," said Castagne, a French national. Meanwhile, Wong decided she had to get out of her day job after finding herself unable to implement any of the changes she wanted to see. "Your role is very siloed, and so the impact you can make is very limited," she said. "That was one of the big reasons why I left a corporate job."

The buy-in

Thirdly, they received buy-in from outsiders. That buy-in, or external support, is essential for entrepreneurs once they start looking for investments or customers. But for the three entrepreneurs who spoke to CNBC Make It, it came earlier than usual — when they applied to join start-up generator Antler.

Magnus Grimeland, Antler founder and CEO, and Jussi Salovaara, Antler co-founder and managing director, speak at the start-up generator's demo day in Singapore on January, 9. 2019. CNBC

Unlike traditional start-up accelerators — which typically help early-stage businesses — Antler looks for individuals with entrepreneurial potential, then helps them find co-founders and develop their business ideas. That approach is potentially more risky, but it also provides scope to find individuals with hidden potential, according to Antler's co-founders Magnus Grimeland and Jussi Salovaara. In Castagne, Fang and Wong, they said they found the three key traits they were looking for. 1. The spike - Something that an individual is really great at, whether that's a personality trait or a passion of theirs. 2. Inner drive - Proof that they're a self-starter and have the ability to motivate themselves and others. 3. Tenacity - The perseverance to keep going, especially when things become most challenging. Early-stage start-ups are often only as good as their founders, noted Grimeland, who is also CEO of Antler. As such, it's important to make sure those individual traits are in place before anything else, he said. "A lot of great start-ups, they fail because people actually gave up, but not because they didn't have a great idea and a great team."

Advice for would-be entrepreneurs

Of course, the entrepreneurial path differs from person to person, and those three factors are just the beginning of a long journey. But as Castagne, Fang and Wong continue on theirs, they shared their best advice for those considering taking the leap into entrepreneurship.

Xinyan Fang, founder and CEO of YoRipe. CNBC