You all have gotten to the real meat of it here. Testing yourself is essential and doing it without the safety net is a requirement at some point. You are not truly alive until you've done it. I'm not talking about the rush of the moment either, but the deep self awareness and understanding that comes from testing your mastery with real consequences.
It's interesting where peoples limits are though. To me it seems reasonable to step out of an aircraft into the night miles from land on my way to combat, but not to ride a motorcycle to work.