@Ceili,
I would say that I've mad an official survey of the people whom I know that are intelligent and creative. Their spelling is worse than the average. The more creative I find the person to be, the worse spellers they are. However, I can't say they try to be better spellers.
On a slightly different note, in the last 10 yrs of my being online (I'm 59), I've noticed my own spelling deterioration and dyslexia, particularly with transposing letters. However if asked how to spell any word, I'd score about 98% correct. It's typing where I fall down.
Perhaps your problem is that you're not as concerned as you think about the correctness of spelling. Or it's an unconscious block ..due to a rebellion of some sort?
(Note: in writing this note, I made 7 corrections by eye and one with help of spell check)