This week's book giveaway is in the OCAJP 8 forum. We're giving away four copies of OCA Java SE 8 Programmer I Study Guide and have Edward Finegan & Robert Liguori on-line! See this thread for details.
Because an inner class is associated with an instance, it cannot define any static members itself.
I think that they could easily have allowed static members in inner classes, but they thought it would encourage poor programs, so forbade it. That may or may not have been a good decision, but we don't gain a huge amount by worrying about it!
Betty Rubble? Well, I would go with Betty... but I'd be thinking of Wilma.