Have you ever heard of the Holy Grail? Whether it's King Arthur, Indiana Jones, or Monty Python, it always seems like somebody really wants to get it. Speaking of those three, "chasing the Grail" is also a great idea for a movie marathon theme.
In your paleontology career, you might feel a lot like those guys seeking the Holy Grail. There might be a project—a hunt for a particular set of fossils, perhaps—that consumes your life for many years.
You'll dig, and chip, and sift through fragments until you're full of gritty brown dirt in places you didn't even know you had. You'll analyze sediment and rock samples 'til your eyes are bugging out of your head, and you'll spend countless hours trying to pin down an elusive fossilized ancient monster-thing that clearly didn't want to be dug up in the first place.
Finally, just as you're ready to give up, you'll find your personal grail in a place you'd never expected—and it'll be in near-perfect condition. Suddenly, all those hours of digging, toiling, and taking the jokes from your colleagues will all seem worth it.
But really though, is that worth it? For the right person, surely. You may not get very clean rolling around in the dirt in this business, but it'll surely feel hugely satisfying to validate all the work you've put in chasing an elusive piece of ancient history.