Language Learning for (Reasonably) Smart People

Where have all the smart people gone?
And more importantly: Where have all the diligent and ambitious people gone? Now one often sees books about language hacks, learning a language while sleeping or through just talking to people. Then there are the 12-steps-to-success-this and master-grammar-by-deconstructing-it-that gurus.
The truth is that language learning is not actually hard in the sense that one has to be smart to do it - thus the title. Reasonably smart is all we need to learn a language. It doesn't have to be a chore either; it can be fun. But we have to do it seriously. We have to put in the effort and put in the time. It takes quite a bit of time. But it is also achievable.
I think what language learners need is a book that clearly lays out how to learn a language properly, without arbitrary shortcuts or absurd time-frames and silly distractions.
I have learned a bunch of European as well as non-European languages and in this book I share both my insights as well as those of other successful language learners and some of the relevant linguistic findings.
The book has three parts:
1) Introduction: The Method
2) Main Part: All the steps learners need to take from beginning to end and a systematic discussion of all aspects of the language journey
3) Final Part: Miscellaneous Problems: 37 short chapters that deal with the details, problems and frequently asked questions
To make the book as useful as possible there are three example cases -> Spanish, Russian and Japanese (which in turn are similar to Italian, Ukrainian and Chinese etc.). Many people want to learn Spanish, Russian or Japanese or one of the languages from their language families, like French or other Romance or Asian languages.
This way, readers understand how language learning generally works and they receive a meta-plan and a blueprint they can use for their purposes. Finally, the concrete cases serve to make the whole thing as clear and applicable as possible.
I have learned quite a few languages myself. I like doing it, and with this book I want to help people who also want to do it.