I know exactly what you mean, though I learned about the miracle of St. Januarius as a kid. It was featured in a National Geographic documentary on Herculanaeum and the modern-day volcanic and seismic risks to the Naples region.
That's where I heard about it too . . . although I read the associated article in the NG magazine, didn't see the TV show.
And that's when I was still an Episcopagan. Thought it was pretty neat at the time (you see how all these events and observations accumulate, and before you know it, you're a Catholic!)