As I'm often wont to do, I checked out This Day in History on the History Channel web site. Besides being the day associated with romance, today is also the day that penicillin was discovered by Sir Alexander Fleming.
Coincidence? Hmmm. How much penicillin has been consumed as a result of "love"?
Interestingly, the History Channel lists today as the day of discovery of penicillin, yet Wikipedia lists September 28, 1928 as the date of discovery.