Thanks to NyQuil, I was feeling pretty good this morning.  Still, I definitely had a cold yesterday, so I would rest today as a precaution.

I was fine at breakfast; I had no symptoms at lunchtime; I played tennis after dinner.  Gee, I guess that cold left!  Another possibility is that I was allergic to something in the Biology room yesterday.  Allergies feel similar to colds, but I did not have my usual allergy symptoms.  I still think it was a cold, but one that I beat thanks to some aggressive treatment and a lot of rest.