When thinking about the end of the world, one would come to realize that their own problems were surprisingly small and insignificant in the grand scheme of things. One would inevitably start to think about what they should do to stop it, to save the world and their lives. At the same time, one may also feel fear about their future and think up plans to protect themselves from this catastrophic event.
Adam, however, felt no such compulsion stir inside him. The truth was that, even if a nuclear war happened at this very moment, then he would still most definitely survive through it.
Even if a new ice age covered the world and plunged the world into eternal winter, destroying civilizations and people alike, he would still survive through the world-ending phenomenon.