Khemaridh Hy did the unthinkable.

In 2015, at age 35, the rising star quit a very lucrative Wall Street career. He didn't have another job lined up -- or even a real game plan of exactly what he was going to do.

Co-workers thought he was nuts. His own parents, immigrants to the U.S. from Cambodia and France, kept asking him when he was going back to work.

But Khemaridh Hy (who goes by "Khe," pronounced "Kay") looked around his fancy New York office and realized something: More money wasn't making him happier. So many people he knew on Wall Street and in Silicon Valley believed if they could "just make" another $1 million or $10 million or $100 million, they would be set and life would be great.

Except, for Hy, that was a lie.

So Hy, a computer science whiz kid who graduated from Yale and shot up the Wall Street ranks to be a managing director at BlackRock's hedge fund of funds division, gave it all up to figure out how to live "a more fulfilled life."

"Nothing prepares you to see your bank account go down," admits Hy, who is now 37 and wears polka dot sweaters, jeans and neon blue Nike shoes. "Even if it was going down from a big number, it still f--ks with your head."

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Ask yourself the hard questions

Hy and his wife Lisa took their baby daughter and traveled. He learned to meditate at least 40 minutes a day. He started a journal. He spent true quality time with his daughter. And he read everything he could about how to live a better life.

It was his family's version of "Eat Pray Love," except Hy calls it "Uncomfortable Introspection." He compares it to going to the gym. It's not fun every day, but over time, you see a visible change.

"My happiness is now between a 9 or 9.5 on a 10-point scale," says Hy. On Wall Street, he thinks he never got above 6.5. A big promotion or bonus would cause a happiness spike that disappeared within days.

Hy started writing a weekly newsletter called "Rad Reads" while on vacation in early 2015 as he was contemplating leaving BlackRock. He would highlight the best 5 things he read or watched that week and give a short summary of his key "life hack" takeaways. He sent Rad Reads to about 40 friends and colleagues. Nearly everyone replied.

"People loved it. I thought, 'Oh my God, this is awesome,'" says Hy, who comes across as humble despite his success. He's open about his failures -- everything from his iPhone addiction (he's taken concrete steps to break that) to his irrational fear of going broke (his wife had to tell him to stop ordering the cheapest beer on the menu every time they went out).

Rad Reads grew rapidly. People would tell friends, "This is an email you'll actually want to read."

Hy says he now has 4,500 subscribers. That may not sound like a lot, but his readers are some of the top stars in tech and finance. Many are in their 20s and 30s. They see Hy as a life coach of sorts -- almost a Millennial version of Oprah.

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Overcoming your fear of failure

"We call him an 'honorary Millennial,'" jokes Kunal Tandon, a venture capital consultant in New York who met Hy at a gathering for tech founders in an East Village bar. "He speaks our language. In a way, he speaks it better than us."

The Rad Reads emails arrive with subject lines like "From Hustle to Wholeness" and "Fear of Failure." His motto is "Be your best self."

The emails are geared toward type-A overachievers. Hy acknowledges that he's speaking to a mostly privileged audience that isn't living paycheck to paycheck, although he's tried to force his readers to question their biases and bubble mindsets.

His biggest realization is that fear -- especially the fear of failure or running out of money -- holds so many people back from doing what they really want to do in life. Even in his own life, he and his wife budgeted for a two-year break, a deadline that is approaching. .

"We're all busybodies, scurrying through the week. Rad Reads is homework Khe has done on our behalf," says Khee Lee, an ex-Googler and Rad Reads subscriber.

How to turn an idea into success

A year and a half after Hy left Wall Street, no one thinks he's crazy anymore.

He gave a TEDx talk in London in October. Several top businesses, including hedge funds, have asked him to speak to their workers about what he's learned on his life journey the past two years. He's active on Snapchat, dishing out daily advice, including his belief that taking extremely cold showers is the ideal way to stimulate the mind in the morning.

Business news site Quartz hired Hy to be its first ever "professional in residence" in September to write "about productivity and the nature of work" and put together an event. Hy already organizes regular Happy Hours and volunteer gigs for Rad Readers to connect in real life.

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The Happy Hours are "amazing," says Tandon. "I met a founder of a startup, a journalist, a hedge fund manager, a nonprofit director." Tandon credits Hy with teaching him to ask better questions and talk to people about more interesting things than just day jobs.

Hy is a natural connector, he says. Within a few minutes of meeting you, he will say, "You should meet so-and-so. I'll introduce you."

In an era when so many Millennials are changing jobs -- and even entire careers -- that kind of networking is coveted.

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What to do in 2017

Hy doesn't think people have to follow in his footsteps and quit their jobs. Instead, he wants people to take four steps:

1. Have more compassion -- for yourself and others. Hy says he would beat himself up if everything in his day didn't go perfectly. Now, he has more of a glass half-full approach. He doesn't let little things blow up his day.

2. Do the "Uncomfortable Introspection." Hy says you have to figure out what you're afraid of and learn to set it aside so it doesn't impact your decision making. For some, this may take meditation. For others, it may come through therapy or journaling.

3. Get comfortable with stillness. Hy has come to value "quiet space." It's become more necessary than ever to unplug for a few minutes a day. He actually taught himself to meditate on super crowded New York subway cars and made his iPhone password extremely complex to prevent himself from checking his phone so much.

4. Live your truth. When you know yourself and what you really want, you finally stop living for money and prestige. It's freeing, but Hy knows it's hard. He now makes a living as a writer and speaker, yet he still has trouble calling himself a writer. He has plenty of moments of doubt where he still feels like a pretender.

"I was an emotional couch potato for 35 years," he says from his desk at Quartz. "I have not lost my edge just because I meditate, cry and have dinner by 6pm now."