London, Feb. 4 : Manchester United star Cristiano Ronaldo has said that he cannot play at his best unless he is being booed.
According to The Sin, he has got so used to abuse from opposition fans, that without it, he gets paranoid.
"It's normal for me now. If it doesn't happen, I'm thinking, `Why aren't they booing?' It's part of football. Maybe they think if they boo I'll lose my concentration - but it doesn't happen because I like it," Ronaldo said.