Thereâs no substitute for practicing with the real thing, yet sandboxes can remove the downside of the mistakes you inevitably make when practicing. At the intelligence agency, weâd always practice and rehearse before an operation in an environment in which it was safe to fail. We treated the practice as if it were the operation itself; weâd do all the things we planned on doing during the operation and tried to predict and respond to all the things that could conceivably happen. If something didnât go as planned, we would adapt. And sometimes weâd fail. Failing in that sandbox, though, provided a learning opportunity with few real-world consequences, whereas failing in a real operation could cost people their lives.