The only sure thing is to live significantly below your means as often as possible. Becoming accustomed to life as a peasant when you could live like a king is what makes you economically bulletproof.

I can go for a decade without another dime coming in the door. If I started using DoorDash and Amazon Prime every day, I'd last maybe 18-24 months. Just barely treading water is actually a great position to be in. It keeps you honest and any amount of work you do find on top of that feels like a windfall. An extra $500/m is a lot if you can make it happen consistently.