The author is to some extent making an argument from experience; it's not entirely unreasonable to ask what that experience is.
For example, if the author is still a student (I have no idea if that is the case) that would go some way to explaining the apparent belief that the job of a software engineer is only to solve already well-defined problems—which is to say, homework problems. We could then discount the advice accordingly.
That is true only to some extent. Information can be valid or invalid independently from it's source.
If you have an idea in your dream, does that mean it won't apply in the real world? Even though the dream is nothing like reality, it doesn't inherently mean that the idea is wrong, it just means that it's not 100% right.
