THEM: may i have the ball?  YOU: you can have the ball if i can have the rest of it.  THEM: no. i'll take the ball and the hat, then you can have the rest.  YOU: i'll take the hat and 2 books.  THEM: you can have the hat and one boo.  YOU: i'm sorry that's not going to work. i'll need the hat and two books.  THEM: you don't need those things. one hat and one book, final offer.  YOU: sorry. that's not going to work with me. i want two books and 1 hat.  THEM: that would give you 6 and me 4. not going to work. i want an extra book. you'll still be getting more than me.  YOU: our values are different from eachothers. you don't know my value, i don't know your values.