Young Money

I saved $100,000 in my 20s and this was the No. 1 thing I did right

Between 2004 and 2012, I lived in one of the most popular and expensive metro areas in the world, New York City, and made about $30,000 a year, and yet, I was able to sock away over $100,000 for use as a down payment for an apartment.

Surprisingly, though, my key takeaway doesn't have to do with either earning or investing.

I had a little help. I had a lot of luck. But, although it doesn't come up much in discussions of personal finance, I discovered that what matters most is simple: other people. If you make the right relationship choices in terms of who you live, hang out and get romantically involved with, it's significantly easier to make the right money choices.

Personal finance experts and self-made millionaires alike stress the importance of creating multiple streams of income. Others teach great habits to develop to save on purchases both big and small.

And those tips are important for sure.

By all means, try to earn like Jay Leno, who, even as an up-and-coming comedian, worked two jobs and banked one salary while living off of the other, or like Kyle Taylor of The Penny Hoarder, who has turned side hustles into an art form.

Likewise, you can't go wrong saving like Matt of "Distilled Dollar," who, along with his fiancee, saves 60 percent of his income and has grand long-term plans, or like Mr. and Mrs. 1500, who managed to hit their ambitious financial goals ahead of schedule.

But the most important decision I made was to surround myself with like-minded people, both romantically and socially.

I was able to save a lot while making relatively little and living in one of the world's most expensive cities without employing a more sophisticated saving strategy than high-yield online savings accounts and CDs.

Though a lot of my success is attributable to good fortune, it also really helped that I coupled up with someone who also prioritized putting money away. Together, we were able to split some costs and skip others, and, most importantly, support each other.

What good is a minimalist mindset, after all, if you're living with someone who eats out two or three meals a day? Eventually you too will succumb to Seamless. And how are you supposed to pay down your debt and concentrate on generating dividends if your sweetie's FOMO philosophy means they never want to think about, let alone plan for, the future?

My boyfriend-turned-husband and I were carpe diem-compatible, which is to say that neither of us cared that much about seizing the day.

Instead, we focused on living large in small spaces. That meant often going to readings, improv shows, story slams and theater so far off Broadway we may as well have been in Queens. That was OK! In fact, it was fun.

We've enjoyed doing New York on the cheap with friends who are wired the same way, people who also get excited about dining out on dumplings and falafel, playing board games and entertaining at home. Peer pressure doesn't stop after high school: Hanging out with friends who have expensive taste can make you feel self-conscious and prone to over-spending yourself.

Getty Images

Most importantly, those several years we were especially frugal, we were able to pay off all our student loans, buy an apartment in the city and then use our financial freedom to experiment with our careers. Now we're both in jobs we've chosen and enjoy instead of stressful, high-paid positions designed to support an expensive lifestyle.

Who needs to retire early when you love what you do?

This is what relationship advice-types mean when they say to make sure you're with people who share your values. If you want to be an ant, don't shack up with a grasshopper. Don't even go out drinking with grasshoppers that often or you'll start questioning your decisions, second-guessing your priorities and, perhaps, feeling strapped, like the couple that makes $500,000 a year and still can barely save.

As Sean the "Money Wizard" puts it, figure out what you want, independent of anyone else: "What makes you happy is not decided by your friends, your neighbors, or the commercials on TV." And then surround yourself with the kind of people who want the same things.

From splitting the check to DIY adventures, "Young Money" helps you navigate tricky financial situations.

Check out more in the series:

Like this story? Like CNBC Make It on Facebook!