Allow me to ask you something: what do you believe the most critical survival skill to have is?You might answer finding food and water, navigation, self-defense, or building shelter.But I'm here to present you with an entirely different idea, that the most critical survival skill (at least when it comes to urban survival) is to blend in.This is what a survival gray man (or gray woman) is: someone who is effortlessly able to blend in with the crowd...