A growing number of young professionals are trying to leave the work world before they're 40, said Steven Kurutz at The New York Times. Looking for "a way out of soul-sucking, time-stealing work," they are embracing the burgeoning FIRE movement — "financial independence, retire early." FIRE evangelists "geek out calculating compound interest" to maximize their savings and find the formula that lets them move from places such as Silicon Valley to more affordable towns. Variations abound: There are advocates of "lean FIRE," who believe in extreme frugality, "fat FIRE" who hold on in the work world long enough to keep up a higher standard of living, and even "barista FIRE," who quit stressful jobs but work at Starbucks part-time for the health insurance. "We all know that a traditional retirement is a thing of the past," said Elizabeth O'Brien at Money. FIRE enthusiasts are essentially saying, "Let's just blow up the whole concept of career, and retirement, and start from scratch."

It's easy to see why the FIRE cult is expanding, said Shomari Wills at Vice: Today's high-pressure office jobs take an unprecedented toll on our health. One infotech worker decided to retire early after seeing her mentor keel over and get carried off on a stretcher. But ultra-early retirement isn't easy to pull off. The key to success is avoiding "lifestyle creep" — the temptation to spend more money as your income rises. Coworkers often start off skeptical, but end up envious. What do you do in early retirement? Backpack around Europe and the U.S.; get in an Airstream trailer and Instagram your camping life; or, in one case, hit the wilderness to become an avalanche forecaster.

Just know before you set out that there's no magic number for early retirement, said Steve Adcock at Market Watch. You'll want four years of living expenses in available cash. And you will end up needing more than $1 million, a stockpile that many in the movement shoot for, to take you through the rest of your life. But guess what? There's no "retirement police" keeping you from making some extra money from your passions. Just be careful to know what you're in for, said Alessandra Malito, also at Market Watch. Factor in the cost of health care; that's something many early retirees dangerously underestimate. If you really want to retire in your 30s, you'll need to cut back on eating out, movies, and vacations. That means forgoing a lot of the "things that make life enjoyable." But even if you don't go all out, you can still take a cue from the FIRE movement and "prioritize experiences over material possessions."