'You're studying history? So, you're going to teach then!'
I know this is hard for some people to grasp, but the history field has one of the most dynamic skillsets of any profession. You require knowledge of literature, ability to conduct academic research, ability to write in an academic format, have organizational skills, have problem solving skills, be able to form theories with miniscule quantities of information, and - anymore - we have to be computer savvy. We'll ignore for a minute that History B.A.'s are also a favorite path of law schools for perspective students.
So, that means I could teach (if I liked being underappreciated and spit on by students and probably the administration). But more likely, I could be a librarian, be a researcher, work in government (local, state, or federal), aid in archeological research, aid in academic research, write, office automation, office administration, secretarial work, archive, work at a museum, work at a historic site, work as a park ranger, be a lawyer, go into politics, work for a publishing firm, work as an appraiser, work as a historian or historic advisor...do I need to go on?
But this doesn't bother me near as much anymore (mostly because I'm employed and am now at a graduate level - that question is easily shot down), so much as this:
"You guys only have to study history though..."
In my undergrad, I worked in the archive where I currently work (though I wasn't getting paid then). Rather, I just worked in the archive and I don't just work there now. Anyway...
Part of my job then was to do the basic historians duty of making heads and tails of what was in front of me. In my case, that consisted of reading through extremely elaborate and detailed technical reports on various weapons systems. I read about ballistic studies, engineering reports, studies on digital azimuth's, fire control platforms, and various forms of climatological impacts. That's just to name a few. I was tasked with sorting these into a database in a searchable format that people could read and understand. So, of the 2,500 entries, I had to read them all, make sense of them, and then parse them into something the general public would actually search for. Chances are you aren't going to be looking for a ballistics study on a gun, but you might look for the firing range or angle of that gun. I had to make sure that data was programmed and available.
Likewise, when a historian takes on a subject, they have to assume specialty expertise on that subject. For example, I could not write a research paper (25-50 pages) on the P-51 Mustang unless I assumed some sort of expertise on the subject. I may need to know things about the Army Air Force, the Air Force, North American Aviation Company, aviation as a subject, and engineering - to know what the P-51 did that was better or worse than its contemporaries. If I'm writing on the history of heart surgery in the United States, I am going to have to have fundamental knowledge on the processes and history of surgery and heart surgery (and treatments) in the United States. That information isn't just present in the realm of history, but to the realm of medicine as well.
A historian's duty, in a dull sense, is to know "stuff", and report on it in such a way that it remains replicable or applicable. It is our job to preserve a period or issue in time and ensure it isn't forgotten, whatever the reason may be. That means we learn history - not as a profession - but as a skill. To a historian, our degree certifies a skill, the knowledge and specialty comes after that skill is procured.