Valentine Day wisdoms St.Valentine is among other things also the patron saint of the Plague victims.

Saint Valentine the holy man now inextricably linked to pastel hearts and Hallmark cards, but he’s the patron saint of much more than love. Bee keepers, plague victims, and epilepsy sufferers also fall under his posthumous jurisdiction.

Despite being one of the most known saints, the exact identity of Saint Valentine is itself rather fuzzy. There was a priest named Valentine, as well as a bishop, who were both martyred in the third century by Claudius II after they defended Christians. The priest was beaten to death and decapitated after being imprisoned. The multiple Valentine identities somehow merged, which accounts for the whole horde of Valentine relics, including numerous skulls.

“The association of Valentine with romantic rites is due to largely futile efforts of early religious Christian leaders to do away with pagan festivals by substituting a Christian observance. February 14 was traditionally the Roman festival of Lupercalia, an important day to honor Juno, the Queen of Heaven and protector of women. The wife of Jupiter, Juno was said to bestow her blessing on courtship rituals or marriages celebrated that day.”

But where do bees, plague, and epilepsy come come in? Well, curing the sick, including epileptics, is one of the miracles attributed to Saint Valentine. In a 2009 paper in Epilepsy & Behavior journal on “St. Valentine–patron saint of epilepsy: illustrating the semiology of seizures over the course of six centuries,” 341 depictions of Valentine curing epilepsy are cited dating back to the 15th century. The plague may have been a later attribution when Europe, struck by the devastating disease, turned to any saint for aid that had any powers of healing. The bee keeping may be more a part of the iconography of fertility attached to Valentine, although sources vary. More here.

What concerns his attribution to the Plague here's a well hidden dark secret:

Valentine Day in Jewish History 1349: A Valentines Day Massacre in Alzace. The Black Death, sweeping Europe in the 14th century, provided an excuse for the citizens of Strasbourg to unleash their anti-Semitism.

On February 14, 1349 – St. Valentines Day – the Jewish residents of Strasbourg, in Alsace, were burned to death by their Christian neighbors. Estimates of the number murdered range from several hundred to more than 2,000. What was left of the Jewish population was kicked out of the city. More on this story here and here.