The rare disorder, in which one side of the brain grows substantially larger than the other, occurs when neurons in the abnormal hemisphere undergo too many cell divisions before they mature.
For every new word you learn in your English lesson, every problem you solve in maths, every new song you learn to sing, a neuronal network grows in your brain and the brain changes.
The problem manifested itself much more often with XFS 1.0 because certain kinds metadata updates were required to be recorded to the filesystem in the order that they occured.