A twentysomething entrepreneur starts a business while holding down another job and living on friend’s couch. He’s trading financial insecurity today for work he feels passionate about and a distant promise of a future payoff.

A fortysomething father of two with a stay-at-home wife walks away from a lucrative legal career without knowing what his next step will be because he can’t tolerate the stress and relentless hours any longer.

A single mother of three gets laid off and decides to start a not-for-profit instead of finding another job in advertising.

Their unique journeys not only challenge the traditional wisdom about the path we “should” follow with our work and careers, but they also challenge the standard rules about money. And yet, they raise plenty of practical concerns: How is the entrepreneur who spends his 20s scraping by supposed to buy a house and two cars in his 30s? How is the fortysomething father supposed to send all of his children to private, four-year colleges and fully retire at 60 years old? How is the single mother going to afford weddings for each of her three daughters?

Work, life, and money are intertwined intimately, and yet they’re rarely addressed together. As the traditional boundaries that used to define “work” and “life” disappear, the conventional beliefs related to money must also evolve.

This is the message of Laura Vanderkam’s new book, All the Money in the World: What the Happiest People Know About Getting and Spending (Portfolio, 2012). By taking on outdated money beliefs, Vanderkam offers a new approach to finances for a modern, more flexible reality. Some of the changes she advocates include:

Be more mindful about what your money could buy. Make purchases that improve your happiness. For many, that means spending on experiences, not things. Using the example of the money we have traditionally paid for expensive engagement rings and weddings, Vanderkam calculates how many trips, periodic bouquets of flowers, date nights, babysitters, and hours of housecleaning that money could buy over the years. These are services and experiences that, in the long run, could bring more enjoyment to a couple than a big ring and wedding.

The single mother who started the not-for-profit may not be able to pay for a lavish wedding for her daughters, but they will see their mother doing work she loves. This will not only set an example of happiness that will hopefully inspire the professional choices of her daughters, but help them prioritize how they want to spend their money.

Challenge the big house, big yard, two car “American dream.” Vanderkam points out that these purchases often come with a longer commute by car, more responsibilities for lawn care, and housekeeping. Studies show that none of these activities increase happiness.