Uh... I think I was not clear enough
... I know all that you described, I went through all of these topics. What bothers me is that I have spent a good time memorizing something that I ended up using to nothing, and if I ever needed it I could just get a book about the topic (remember, I know the basics). I have spent too much time studying advanced mathematics when I could have given more attention to logic and more pratical day-to-day topics.