My little brother spent years as a screenwriter in Hollywood. His big claim to fame is co-writing credit for Toy Story 2, which has box office sales of roughly half a billion dollars. He has taken a meeting with Steven Spielberg, had dinner with Steve Jobs, and now teaches at UCLA’s night school.

A glamorous life, right? Then beware. Screenwriters do most of their work on spec, and fights to get paid are legendary. So when Chris Webb learned to become a screenwriter, he heard again and again this advice: Spend your second million dollars, not the first.

This might seem like a strange time to promote frugality, what with full-service remodelers in our 2018 Remodeling 550 reporting roughly 8% more revenue than last year and replacement contractors recording an eye-popping 41% gain. Actually, it’s a great time, for several reasons.

First, profitable conditions are likely to continue for several more years. The Residential Remodeling Index produced by Metrostudy, a sister company to REMODELING, finds that economic conditions for remodeling today are even better than they were at the housing market’s peak in 2007—and they’ll keep improving through 2020. And at the Joint Center for Housing Studies of Harvard University, the prediction is that home improvement and repair spending will rise 6.6% this year to $414 billion.

Second, comparisons of a decade’s worth of forecasts and results by Remodeling 550 members prove that remodelers are pretty bad at predicting future revenues. Usually, you’re overoptimistic. Failing to forecast accurately is understandable for an industry in which you’re lucky if the work pipeline stretches six months into the future, but it’s also a reason to avoid exuberance.

Finally, the nation is likely to swing from bull to bear status even faster next time than it did a decade ago. Nobody wants to get caught. So when it happens, you’d better be ready.

In a recent webinar, Remodelers Advantage suggested having enough cash to cover four to six months of expectations. Even after Microsoft flourished, Bill Gates wanted it to have enough money to last a year without recording a penny in new sales. Build your nest egg now, and spend your second million dollars.