Great UI == Damn Near Impossible

Getting a User Interface right is like scoring a 52 at your local Golf Championship?  Ain't gonna happen.  I'm currently working on a brand new UI for our users.  They want an easy way to edit data.  Great.  I'm guessing they're meaning efficient and intuitive.  Well easy for me isn't easy for you.  Actually, quit the opposite.  If you take my Dad for instance, who is in his 70's, you are going to get someone that is not at all that interested in typing CTRL-Z to undo his changes.  In fact, unless he gets a giant icon on the screen that gives him a very obvious indication that he can actually undo his changes, he won't even know the feature is there.  On-the-other-hand, if you make me pick up the mouse to do anything I'm going to get pissed off.  So, that simple case tells me that getting it right for everyone is damn near impossible.