I am just a guy who learned Spanish and became a Spanish professor. I wasn't born speaking Spanish, nor did I speak it growing up. I learned it in college and through study abroad, just like my own undergraduate students. I learned to write in English and in Spanish by writing. I gained knowledge of my field by studying it, like everyone else did. I am a realistic model for imitation, then. Not that you would want to imitate the worst aspects of my personality, of course!
Being a professor does not require extraordinary intelligence. You have to be on the studious side, of course, but once you reach a certain threshold you are fine. The rest is up to you. Your work ethic, your determination. Chances are, if you are professor you will notice that there are people dumber and smarter than you in your same profession. There will be range of people from "dumb as on ox, why is this person doing this in the first place," to absolutely brilliant. The dumb as on ox types are probably not even dumb in the literal sense, just ill-prepared or intellectually lazy.
The other way of thinking, however, is that it is very difficult to do what I've done. Although any idiot can get a PhD, many idiots fail to do so. I might look like the average more studious than average guy, but I am more intense and ambitious than most people even in the academic world. My father was an academic, so I absorbed those values at an early age. I had an 8 to 9 year advantage over people who became academically serious in the later years of college, for example.