It’s often speculated that Valentine’s Day has its roots in the ancient Roman festival of Lupercalia, and it’s not hard to see why. Lupercalia was observed on February 15, and involved fertility rituals — albeit along with animal sacrifice and ritual whipping. Yet the link between this pagan festival and the Christian feast day that morphed into our modern ode to love and romance is murky, and indeed may be little more than coincidence.

At its peak, Lupercalia — which dates back to at least the sixth century BCE, predating Christianity by centuries — was a really wild time. A group of nude Roman priests kicked off the events in Lupercal Cave at the bottom of Palatine Hill with the sacrifice of a dog and at least one goat. They painted themselves in the blood and wiped it off their skin with milk-soaked wool, then cut strips of goat hide and whipped women on the hands with them to promote fertility.

As time went on, Lupercalia mellowed out, and the nudity dramatically subsided. Yet it was still too much for Pope Gelasius I, who forbade participation in the festival at the end of the fifth century CE. One common theory is that he supplanted the pagan festival with St. Valentine’s Day, also known as the Feast of St. Valentine, though recent historians have shed doubt on that claim. For one thing, St. Valentine, a third-century Christian martyr, had no connection to love or romance. In fact, the holiday didn’t get its modern association until Geoffrey Chaucer wrote a poem linking St. Valentine’s Day and mating season in the 14th century, some 900 years after the holiday was established.

Perhaps because of the universally uplifting feeling of starting anew, you can find similarities between the lively New Year’s celebrations found in many countries today and those of the oldest recorded civilizations. The ancient Egyptians, for example, shared huge meals and partook in music and dancing to commemorate the pending flooding of the Nile with the festival of Wepet Renpet, meaning “opening of the year.” And the Babylonians of Mesopotamia enjoyed their own extended gala some 4,000 years ago with rituals that may have included a prototype of our modern-day New Year’s resolutions.

Held in March to mark the start of the planting season, the 12-day Babylonian festival of Akitu —which began on the first new moon of spring — was a time to honor the supreme god Marduk, his son Nabu, and the other deities who watched over the people. For the king, this included a humbling ceremony in which he was stripped of his regalia, struck across the face, and dragged by the ears by the high priest to atone for any sins committed. It’s believed the rest of the common folk, spared of such physical punishment, instead engaged in prayer, promising that they would repay their debts and otherwise conduct themselves in sterling fashion to please the gods.

While the Babylonians may have been the first to introduce these promises to a celebration marking the start of the year, the Romans were the first to deliver theirs in January. For that we can thank the wide-reaching Roman calendar, which moved the first month of the year from March to January. Named for the two-faced god Janus, who both looked back at the past and faced the unknown future, the first month became a time for officials to pledge their vows of loyalty to Rome — a custom that continues in the less urgent but no less earnest tradition of the countless people who pledge to get off the couch and hit the gym in the new year.

The Roman Empire is responsible for countless innovations that are still used on a daily basis, but it would be putting it lightly to say that medical science has advanced quite a bit since Rome fell. Given that — as well as all the gladiators, wars, and assassinated emperors — it shouldn’t come as too much of a surprise to learn that life expectancy in ancient Rome was just 35 years. Yet the real culprit behind that figure is actually the infant mortality rate at the time, as some 25% of babies born in the first century CE didn’t make it past 1 year old, and only half survived past the age of 10.

Life expectancy is an average, and one that has tended to increase over time, but lifespan hasn’t actually changed much in human history. Indeed, it was not uncommon for ancient Romans to live to a ripe old age. Gordian I was 81 when he became emperor of Rome, and Roman statesman Cicero’s wife Terentia lived to be 103, for instance. Pliny the Elder (who, despite his moniker, lived to be just 55 before dying in the eruption of Mount Vesuvius) was particularly impressed by one centenarian he studied. He wrote, “The solitary instance of Xenophilus, the musician, who lived one hundred and five years without any infirmity of body, must be regarded then as a kind of miracle.”