This Week's Topic:
Secret Identity: Do I work on the side to make ends meet?
Do I have a partner in crime?
How long was I at it as a writer before I could successfully quit the day job, or have I quit yet?
It's that last question that many authors use to gauge their success, which...isn't a reliable metric. Being a creative means there are seasons of feast and famine, and famine is more prevalent. You may have one six-figure year followed by a year in the low five-figures followed by a year in the upper fives chased by a year where you don't make 4 figures. Revenue from sales is, by its nature, unstable income. Even if you drop a new book like clockwork, there's no guarantee that Book 3 will sell even a fourth of Book 1. Some series tank for no reason while others rise like a phoenix from a backlist. Gods forbid you're depending on a publisher to pay your royalties as part of your annual income...Sure, royalty checks are more attainable than winning the lottery, but even lottery payouts occur at a fixed amount and on schedule.
You need to be a master of budgeting and a hard-core realist (even a pessimist) when forecasting writing-derived revenue. There's a reason finance companies don't like to give creatives loans. There's a reason a lot of full-time authors have spouses who own the burdens of reliable income (and health insurance) or they have investments that supply livable income. There's no shame in being part of the hustle of having a job that pays your bills while also having a job that feeds your soul.
As in all things, balance is necessary.