Making It Real

An interesting thought just crossed my mind. I talk a lot about how to make characters more 'human' and real on a page. Things like quirky personalities, idiosyncrasies, furnishings, atmosphere, all help make things more believable. How many writers give their characters disabilities, or illnesses to deal with. How often do you find a character, even a supporting one, with eczema? I'm not making light of it, I mean it would make characters more real. Give stories more of a well-rounded personality and feel. There are so many aspects of real life that we'd prefer not to exist in fiction, but makes fiction more real.