I recently did a informal interview with some undergraduate students about grad school & academia (part of an assignment for them). I certainly did not know much about academia when at their stage. The students seems a little surprised by a few of my anwers. Here are a few things
Not every professor is a professor.
There are professors, lecturers, postdocs, etc. Many of these folks may teach a class from time to time. From the student's perspective perhaps a teach is a teacher. Though these folks may have very different status in the department.
Not everyone is a student or professor (ie what is a postdoc?)
They had no idea what a postdoc was, or more generally that there are people in the department who are mainly here for the research.
Everyone is, to some degree, winging it. Your career decisions may be as much serendipity as serious long term planning.
What drew you to your field? I turned to the wrong page in the class bulletin and saw something interesting.
What about your research topic? My undergrad advisor handed me a paper and said "figure this out"
Why did you go to the particular graduate school? I got in.
Ok, not that decisions were due to random chance. But there was not detailed grand master plan that I hatched junior year.
Relatedly, you don't have to pick a specific research project early and stick with it. They seemed a little surprised that I'd bounced around a bit while figuring out what I wanted to do. And even when I applied for grad school I wasn't totally sure.