Have you noticed?  Hard not to, isn't it?  Is it age or is it stress?  There are two schools of thought here...Of course there's the genetic argument.  According to ABC News.com:

Most medical experts say that genetics plays the largest role in determining when a person goes gray, but new research seems to back the theory that ...stress can turn the head white.

Really???   REALLY??   Everybody's grandma in HISTORY could have told you that!!!

This subject, ( one near and dear to my heart-LOL), caused a song parody to spew out...  I was thinking if Obama could have talked to other graying Presidents, what would they say to him?)  Here it is, with apologies to Alan Jackson...