I was reading the Master Switch, and it talked about how Heaven’s Gate was a failure so huge that it crashed the United Artists studio.
This prompted an idea.
The reason that a financial failure can crash a studio is that they need capital to cause the projects to happen. This happens because they need money for equipment (i.e. you need money to interact with the general economy), and because they need to pay people (i.e. they need money to hold the group together).
If you invalidate those two things, then an organization becomes unkillable.
If you have a group of people working on something that they would want to work on whether or not they got paid, and they didn’t need to get things from the global economy, then the organization can survive any amount of financial damage until the point that police come in and repossess or arrest people.
I think this is what made a few Stoics so formidable. They were okay with losing everything, and would continue doing things in that state. There was nothing you could do, short of killing them, to make them stop.
When Gaius Musonius Rufus got exiled to one of the most barren islands in Greece, he wrote a lot, discovered springs, and gathered followers. He directly improved his quality of his life without any external support.
Knowing that you could live with any consequence, doing what you want regardless of external circumstances — if that’s not relentless, I don’t know what is.