Let's say once and for all...it is possible to learn a language quickly? my method, your method :)

Ok long story short, first forgive me for the mistakes but again it is not my mother language so…have patience please (i’m italian not spanish).
The big question for me is this…it is possible to reach very quickly a level where i can start to enjoy the language more than studying it? ( I enjoy even the start of the art of learning a language but in my mind is even better when you reach a level where you can read or listen things that matter to you, at the beginning is all about "hello, i want a coffee, how much is it? how old are you bla bla).
So the goal is reach a good passive vocabulary that allow you to start reading about history maybe, or some books, or see movie with a good understanding of what’s going on (in the case of reading of course use of the vocabulary it’s ok, but to find 1 word every 10,15 not every 2 or 3)
The classical method is take some books for beginner, make lessons, make exercises, learn some words at time etc… but it takes a lot of time to reach that level.
So memonic… how do you use it? step by step please let me understand! I can use them to learn words quickly with the method above but again is slow, very slow…
Better to find a list of most used words and learn it (by mnemonics of course) ? if yes…how much? 1000 words? 2000?
and then? start to do what? I’m asking a step by step journey to understand how you learn a language! And it’s more about how to use the words (and how much…) you learned than how you learn them!
(yes of course if you have time maybe I will appreciate also your method)
I’ve learned english but in a lifetime, spanish but it’s so similar to italian that…i cannot say I have studied spanish! I’m learning chinese and japanese…chinese is for me very hard when it comes to learn words few sound, tones…a nightmare but now i’m more interested in learning japanese with mnemonics so help me :slight_smile: (a japanese word it’s for me very easy to learn with mnemonics or…better…it’s easy to find a mnemonics for me to learn a japanese word) so i need a method, a quick one (even if it’s a year method it’s ok but if it’s quicker than mine…i will be happy)

You might want to check out the discussion about tips for learning vocabulary with mnemonics for ideas.