This can also be a good rule of thumb for entrepreneurs investing in ideas or potential new features, or even for ordinary employees managing their careers.

You can get surprisingly far in life simply by cutting your losses early. If you majored in art history, got to junior year, and then suddenly realized there are no jobs available - switch your major! Or transfer, if you have to. If you hate your job, find another one! If your skillset is out of date, learn whatever the new hotness is. If you picked a dead-end field that's being disrupted by a new industry, switch to the new industry.

Many people don't do this, because of a couple of cognitive biases: sunk cost fallacy and fear of the unknown. But they ignore that they've learned new information in whatever their old role was, and that the future is usually much longer than the past.