Moments when one ceases to have will for life or hope for surviving, makes one free himself of delusions that bind and cloud thoughts with complexity and despair efficiently.
It's a moment i'd call 'Extreme Truth', or a 'Naked Truth' where one faces Reality that is Wild, Savage, Unknown and Uncaring, and Stranger than one has thought before.
It's like watching Unknown Beast in it's eyes and proceeding to death or life as it observes somewhere there.
These are moments when one stops to care whether he lives or not, enjoying fearless, somehow a magical rush of adrenaline. This gives strength to survive and perhaps a wild ride that is remembered for long...
Quite addicting and dangerous experience, especially first time when one is totally unprepared for it.