Birmingham City goalkeeper Ben Foster admits he lacked the ruthless streak to survive at Manchester United.
The England star spent five years at Old Trafford trying, but failing, to share the 'win at all costs' mentality that gives Sir Alex Ferguson's club their edge.
He said: "I enjoy football, and I want to win. But at United it is at a different level. It is the end of the world if you draw. I just thought it was too much, it gets out of hand and it is ridiculous. They have had 20-odd years of winning and people like Gary Neville it's in their DNA. Even in training you'd see tackles flying and little scuffles. It's very intense.
"People say if you are in the team you kind of adapt to that. And I love winning. If I'm playing a video game, anything, I want to win. But the United thing is another step up the ladder of mental toughness and it's not really me.
"I like to go training, then once I'm home I completely switch off. Even if I have builders round my house wanting to talk about football and stuff... honestly it does my head in."
