Sadly, these are the kinds of things that I spend my time wondering about.
Just WHY do we say "Bless you" when someone sneezes?  It seems such an odd thing to do if you really think about it.  And, we don't say bless you when someone coughs. 
Anyway, I just HAD to do some research and I thought I would share it in case any of you were wondering too (probably not).  

Dear Yahoo!:
Why do we say, "God bless you" when someone sneezes?
A. H. Choo (see, I'm not the only one who is is wondering about this!)

Dear A. H. Choo:It does seem a rather strange thing to say. You contort your face, expel mucus, and onlookers wish upon you a blessing from the big man. Very strange indeed...
The origin of the "bless you" tradition is not entirely clear. The urban legend experts at Snopes.com list an impressive number of possibilities. One involves the (hopefully) mistaken belief that a human's soul might escape through a sneeze. Saying "God bless you" wards off Satan while the soul is temporarily vulnerable.
Another story veers toward the medical. Once upon an unenlightened time, people believed that the heart stopped during a sneeze. A hearty "God bless you" set the ol' ticker back in motion. Keep in mind these were the days before defibrillators and HMOs.
Interesting, but the most popular theory comes from the Middle Ages. During the bubonic plague, a sneeze was believed to be a sign of impending death. "God bless you" was "a way of commending his soul to the care of God." The phrase may have also come in handy to protect oneself if someone nearby sneezed.
Today, "bless you" is more a sign of good manners than a shield against death.
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So, there you go. 
This is how I spend a lot of my time - chasing down meaningless bits of information! 
I really should be cleaning something.