What ever happened with "chip on the shoulder", "proving your critics wrong", "cowboy/man up", "we against the world", "sticks and stones may break my bones"... ?
"Positivity" is great. It makes a lot of people feel good about things...but then you get punched in the mouth on the field, and no amount of "positive vibes" from discussion boards or YT is going to make you come back from that punch in the mouth.
Myself, I don't want "positive" vibes, I want 2009 vibes, after the Saints lost the last 3 games of the season, after talking heads started talking crap after the Dallas loss, saying how rusty the Saints were going into the playoffs, then after totally demolishing the Cardinals, the coach coming up on live TV saying "so much for being rusty".
I think that is what some refer to as "killer instinct", "mind of a champion". And that starts with the HC.