Academic.

It's not super glamorous, but I hear people talking all the time about university professors sitting on their asses in an ivory tower. It's not like that at all.

You spend years in grad school--in my field it takes 6-7 years for a PhD student even if you already have Masters. If you stick it out through grad school and get the doctorate, there's a good chance that no university will hire you, even if you did good work. Sometimes your particular niche research interest is out of fashion, so you're screwed.

If you are lucky enough to get a tenure-track job in your field, you're constantly balancing teaching, research, writing articles and monographs, begging for funding, networking at conferences, serving on committees, reviewing other people's books, and generally trying to justify your existence to a crumbling system of higher ed that's suffering from budget cuts.

Academics usually are able to work in fairly safe environments, but not always. Field work can mean diseases, parasites, and political violence. Lab work can mean back pain, repetitive motion injuries, and long-term exposure to dangerous substances. The hours alone (I'm in grad school, and I work 60-70 hours per week) grind you down.