Having been mathematical geniuses could not prevent Georg Friedrich Bernhard Riemann, Kurt Gödel and John Forbes Nash from acting nonsensically. The first one tried to prove the truth of the Bible mathematically, the second one (out of fear of possible poisoning) committed suicide by starvation, and the third one was convinced that aliens were communicating with him.
Although he was not a mathematical genius, Rüdiger Gamm was genius enough to mentally calculate 81 to the 100th power. Scientists were so impressed that they regularly subjected him to PET scans while thinking. Rüdiger's brain was so busy calculating, that he was unable to do the elementary calculation that each scan exposed him to radiation 700 times stronger than an ordinary chest X-ray.