The Flu

I have been under the weather since Monday. I am growing impatient because I normally rebound rather quickly when I fall ill. I was told by a doctor here in NZ that I have the flu. While trying to will myself well, I thought about the phrase the flu. Why is it that when you have influenza it is said that you have "the flu?" Why is "the" attached to it? Why not I have influenza? I guess people say I have the measles or the mumps, but no one every says that they have the cold. Is it a sign of severity? Please attribute the last ramblings to the lack of effective flu medication.

By the way, more pictures are on their way soon!