Important lesson to learn in kindergarten: let other people talk too. Sharing isn't just about toys, it's about talktime and teacher-attention. All of these things are finite and desireable THUS ought to be shared evenly around the classroom.
You'd think most people would learn this by the time they hit grad school -- no?
you know what, I'd make a great dictator of the world, if I could just tell everyone how to behave all the time. How about that, God?