There really are many people who have a complete lack of common sense, even if they are considered intelligent in other areas.
I remember one particular lady who was a solicitor by trade wondering why, after so many manicures, her nails were paper thin and dry. It eventually came out, that she soaked them in household bleach every week to make them white! So, an intelligent woman, wasn't able to make the corrolation that bleach, which is used for destroying germs and can strip the colour clean out of a black dress, wasn't 'good' for her nails.
Plenty of academia but daft as a brush! I tell ya!