Java enum inheritance

Example stolen from here

Because adding elements to an enum would effectively create a super class, not a sub class.

Consider:

 enum First {One, Two}   
 enum Second extends First {Three, Four}   

 First a = Second.Four;   // clearly illegal 
 Second a = First.One;  // should work

This is the reverse of the way it works with regular classes. I guess it could be implemented that way but it would be more complicated to implement than it would seems, and it would certainly confuse people.