Many years ago I read an article (which I can't seem to find) that had the following key points:

- Very smart guy

- Had some kind of blood circulatory issue so reduced oxygen to the brain

- BUT was a very active cyclist so has very good cardio

- due to both of the above, he was getting enough O2 to be functional but effectively had a lower IQ

- circulatory issue was eventually identified and then corrected

His comments (paraphrased):

"Being less smart was kind of a blessing. Instead of getting frustrated when things weren't working when there were obvious solutions, my attitude changed to just accepting things.

As soon as my circulatory issues where resolved, I went right back to being frustrated."