A failure means you took risk, which is something you should do if you want to push the boundaries. So you did do something right. No one would suggest you did

A failure means you took risk, which is something you should do if you want to push the boundaries. So you did do something right. No one would suggest you did everything right. Conversely, absence of failure may mean you took a calculated amount of risk and it paid off. But it could also mean you were overly conservative, didn't push the boundaries, and took a minimum of risk. There's no way to tell the difference purely from the absence of failure. The worst outcome is when a failure happens and you though you were very conservative but actually had no idea what the real risks were. That's the Challenger situation.