Making the probably safe assumption that most of you fall into the latter category, I'll just summarize it here: Calculus is important, and it forms the bedrock for the study of physics, engineering, economics, and essentially every other damned thing we use each day.
Including your mom.
The invention of calculus is now widely credited to both Isaac Newton and Gottfried Leibniz. Newton almost certainly came upon the idea first around 1666, but he didn't tell anyone about it, because he was kind of a wierdo. Leibniz, starting in about 1673, came by the discovery himself from a slightly different angle, also developing a much better method of notation that we still use today. Leibniz then formally published his results in advance of Newton, although Newton's papers had been circulating informally for some time. Whether Leibniz saw these papers or not would cause no small amount of hair-pulling among the wider world of math groupies.
Seriously, this was really important to a lot of overly thin dudes.
You see, having the inventor of calculus hang out in the same social clubs as you was really important to these guys, and for years afterward these math groupies nearly came to blows over whose champion invented calculus first. It wasn't until decades later that everyone calmed down enough to acknowledge that they both basically invented it independently.