Glory
What if you're the one on the research team who, by dint of hard work and a dash of luck, stumbles onto the protease inhibitor that eventually is the foundation for drugs that transform AIDS from a deadly disease to a chronic one? It did happen, back in the 1990s. Mini-versions of these breakthroughs occur in pharma labs all over.
Glory stems from being able to improve the health and daily lives of your fellow humans. Kudos from your fellow scientists and letters from grateful people helped by medicines leaven your workday. Who couldn't be warmed by a note from someone saying: "Thanks for coming up with the pill that cured my irritable bowel syndrome. I'm hiking the Sierra for the first time in years, and I don't have to pack a diaper. My life rocks, thanks to you."
How's that for a feel-good moment? Sure, any career path will have its twists and turns and potholes, but a career in the pharmaceutical sciences also leaves you with that sense of accomplishment and satisfaction. Each day can bring a triumph, small or large. After all, not a lot of people can say what they do actually makes people healthier.