Did you ever encounter a computer virus on your machine and were thinking that it is no more "your computer"? What I mean is that the PC behaves in different, not known before patterns. It may slow down, react differently during your standard use and may seem weird in its behavior. Your computer encountered "personality changes".
As I wrote a couple of times, my son/the family has been dealing with epilepsy caused by a brain tumor. Fighting the cause for the seizures and damming them is one thing, coping with the changes to that person is another. A big impact on family and social life may have the personality changes caused by epilepsy. When your kid gradually slows down speaking, when he becomes more aggressive over time, when your child over time has more and more trouble remembering things, you know that you will have new challenges added to the core issues, the seizures.
For a computer virus there is usually a cure by cleaning the computer through different ways. For epilepsy damming the seizures through drugs or trying to remove the cause through surgery are first steps. Thereafter, dealing with the personality changes is a long road ahead. In the case of my son, we are hoping for the best. Next on the list will be to break free, not from Oracle :), but from medication...