I prefer to call it your gut instincts, I am always getting into situations that my brain tells me to fold that K/3 suited or A/2 off against an all-in shove, after all besides a flush draw I really only have 1 over card but sometimes I get a curious feeling in my gut that tells me to call.
Sometimes I follow my Brain and fold, other times I follow my Gut and call, it all comes down to how strongly you feel about your chances.
I was once heads up against a player who pushed all-in pre-flop and without looking at my cards I called, he turned A/K off and I turned over 6/2 off he laughed and said how stupid I was calling without looking and the flop and turn did nothing for either of us, then the river came a 2 giving me a pair and I said who is stupid now and laughed as I took him out and won the game. I said to him if I had looked I would have folded the 6/2 but by not looking I won.
Call it luck! call it Gut Instinct! whatever it was it was all good for me.
