It may sound amazing bordering on bizarre but I can personally attest to this phenomenon. Years ago I wanted to be a writer and I actually wrote quite well. For example, you can find my name in two editions of Writers Digest (November '96, pg 43, #8 in Mainstream/Genre Short Story Winner, and November '95 pg 41 #16 in Mainstream/Genre Short story Winner). I also published a SCI-FI/Fantasy Audiozine called 'SCYWEB BEM' (ISSN 1559-3363) from 2004-2007
In 2007 I had a stroke after 2 head injuries in 2 days. Afterwards, I lost all desire for creative writing but eventually noticed I was developing a strong penchant for art , especially 3D art. I can still look at a sentence and immediately tell you if it is constructed correctly, but I care nothing for it. The passion I once felt for writing now seems to target artwork instead. (Not that my art is any better than anyone else on this board. I know its not. I just have the passion for it).
The doctors say that this isn't surprising. A piece of my brain no longer functions, and other parts of the brain have stepped in to help out, so to speak. But those parts that are 'helping out' also carried their own abilities, and the constant effort to relearn things has strengthened those parts, and so have enhanced the abilities contained there.
On the other hand, my ability to do math in my head now sucks to the extreme. If it weren't for calculators and spreadsheets I'd be at a loss.