I haven't time to be a top contributor, but I have nearly 10,000 points. I just have been mad on astronomy for I would guess twice as long as you have lived.
Reality check: If you were mad about a facet of astronomy, say meteors and comets, and read all literature and went out to view all comet and meteor apparitions that came along, in very little time you could be an expert in that facet, and know more about it than most astronomers.
The reality is that professional scientists of any kind are usually expert only in the area of their research. In an astronomy degree there isn't time to get into the depth of each facet of the subject, certainly not like you could do in a few years on one facet, and by the time the scientist gets into doctorate, he/she is really specialising.
Astronomy is a huge subject - nobody knows everything, and even pros will generally only know a lot about a small part. People have to get out of thinking that scientists know everything. If you have an inquisitive mind, you can get as broad a knowledge as any scientist, without having to do a day of college. And in many cases, scientists are so channeled into their facet of science that they lose sight of the overall picture.