There have been a variety of studies that seem to demonstrate that over zealous cleanliness can have an negative impact on the human immune system. Science Daily has an article on research at Duke suggesting that the higher incidence of allergies in nations with more fastidious habits is due to their immune systems not having to confront the diverse soup of microbes and allergens found in the habitats of less fastidious nations. There’s an important lesson here for those paying attention: stop vacuuming and cleaning obsessively and let a little mother nature seep into your house – you’ll sneeze less. This also validates the cleaning strategies of bachelors like myself – less is more, baby!