How can you not be interested in learning about the oxygenation of the early Earth's atmosphere or the fossil evidence for the evolution of tetrapods? How can you not want to understand how geologists infer paleoenvironments from sedimentary rocks? How can you not want to hear about the latest discoveries from the surface of Mars? This is cool shit!
The only thing that somewhat ruins it for me are the small group of students who always begin each semester sitting there in class, even on the first day, looking bored. Really? I want to tell them to get the fuck out and go work at McDonalds if they have no intellectual curiosity. College is truly wasted on some people! If I was independently wealthy, I'd go back and study something else (maybe math because topics like number theory are awesomely cool).
It's nice to have a job one looks forward to going to each morning.
Study Earth History and find out!