Not at all..but that's what makes life so interesting.
When I started thinking about a career in astronomy in elementary school I had no idea what astronomers actually do. I just wanted to 'study the stars and outer space'. By High School, I was still just in love with being in touch with the stars and galaxies and cosmology. I still didn't know what astronomers really did. I had never come across a single research article in astronomy, and what I read in Sky and Telescope seemed easy enough to learn. It wasn't until I met my first astronomer at UC Berkeley that I began to realize just what the profession was all about. I loved cosmology, and black holes were not yet in the popular eye, but general relativity fascinated me because it sounded like something straight out of science fiction. For my undergraduate years I studied what I could of 'GR' and decided I wanted to be a cosmologist. By my Senior Year, I had taken a graduate-level cosmology course and a General Relativity course, and had also begun to size-up just what my competency was in physics and mathematics. Even with nearly a straight-A average ( 3.87 ) in these areas, I realized one day that being a theoretician was not what I felt comfortable about. I really felt like I was working at my limits, with nothing left over to be creative with in an area of astronomy that would be highly competitive.
Once I got into Graduate School at Harvard, I worked my way towards a PhD, but I mostly thought I would spend my first few years being a 'post Doc' and then land a job in the academic world doing my own research and teaching undergraduates. I had no thought that there would be other possibilities.
Well, today I still do my own research whenever I can get grant money from NASA to do this, but I never got the 'call' from academe to become a professor. You see, getting into college teaching has nothing to do with whether you are a good teacher. All through my life, people and professors have remarked at how wonderful a teacher I am. My biggest frustration professionally, is that I am not 'allowed' to teach. All I can do is get time at various adult education centers at the Smithsonian and John's Hopkins University to teach 8 lectures a year. Occasionally I get an article accepted at one of the popular astronomy magazines...but that's it. The one big thing I wanted to do professionally...to teach others about astronomy...is the thing that this life has denied me easy access. Sure, I am still doing various kinds of research, but it is not in general relativity, and only moderately has something to do with cosmology.
I guess you would say that, no, my dreams for what I would be doing as a professional astronomer never materialized in the way I had hoped they would. But my biggest disappointment in life is that I never made it into a professional teaching situation. Had I known how bad college teaching in astronomy would be, I would have become a High School teacher instead. But I cannot even get into that profession, because now that I have tasted what research is like in astronomy...I like it a lot and do not want to give it up!