The Half-Life of the Common Cold

When you catch a cold, you can expect three to five days of sheer misery, with no sympathy from the people around you, who are all wondering why you'd be foolish enough to catch one in the first place.

Honestly, that phrase.  It makes it sound like you went out hunting for it.

But then, suddenly, the worst is over and you are on the mend.  You wake up one day and your cold is roughly half as bad as it was yesterday.

And tomorrow, it will be half as bad as it is today.  And so on.

Which means, of course, that colds never actually go away.  They just diminish, half at a time, until they blend into the background of urban hacking or pastoral hay fever. 

Or until you catch another cold.