You must sacrifice the pleasures of today for the freedom you will earn tomorrow. In my 20s, I shared a studio with my best friend from high school and drove beater cars worth less than 10% of my annual gross income. I'd stay until after 7:30 p.m. at work in order to eat the free cafeteria food. International vacations were replaced with staycations since work already sent me overseas two to four times a year. Clothes were bought at thrift shops, of course.

Real-estate crowdfunding ($9,600 a year): Once I sold my SF rental, it was natural to reinvest some of the proceeds into real-estate crowdfunding to keep sector exposure. I didn't invest a lot in some of my favorite real-estate investment trusts because I felt a rising interest-rate environment would be a stronger headwind for REITs. But if I could be more surgical with my real-estate investments by identifying specific investments in stronger employment-growth markets, I thought I could do better.

Managerial accounting defines residual income in a corporate setting as the amount of leftover operating profit after all costs of capital used to generate the revenues have been paid. It is also considered the company's net operating income or the amount of profit that exceed its required rate of return. Residual income is normally used to assess the performance of a capital investment, team, department or business unit.