John McEnroe Thinks You Are Crazy

The dude wacking himself in the above video is Mikhail Youzhny in a match against Spain's Nicolas Almagro at the Sony Ericsson Open.

Youzhny got upset after giving up a point on an unforced error so he did what any sensible person would do ... knocked some sense into himself.

I love how the Spaniard goes over and laughs at the silliness of the whole mess, but if I were Almagro I would have been pissed that Youzhny got time to think about the match in a break he set up with his head.

Youzhny ended up coming back in the match and winning, and could only imagine what he would have done to himself had he lost.

He probably would have enlisted the help of fellow Russian Maria Sharapova to hit tennis balls at his own set for hours on end.