Double Dispatch Principle or the "Shit Hits the Fun"

The other day I was thinking about Double Dispatch Principle and it's benefits and came up with the following code sample:

public class Air
{
}

public class Fun
{
   public void Run(Air air)
   { }
}

public class Sheet : Air
{
   public void Hit(Fun theFun)
   {
       theFun.Run(this);
   }
}

public class Program
{
   public void Process()
   {
       var theFun = new Fun();
       new Sheet().Hit(theFun);
   }
}