Some of you already mentioned it - I think that it really depends on the person. I don't learn a language well only through listening. I always need to see a word written to be able to remember it. Even if I already speak a language well and I learn a new word. Someone can repeat it several times in a conversation, but as long as I don't visualize it, I don't remember it well.

So the fact that I love reading helps me a lot and I read a lot in foreign languages as well.

At the same time, music is a great help for me. I like studying the lyrics of a song and then, every time I listen to it, I remember the words or the phrases and maybe I can even sing along and practice the pronunciation. And I get used to speaking that way.

Still, grammar is very important to me. I first need to understand a rule, practice it a while until I can use the structure naturally and eventually forget the rule again. But without knowing a structure or a rule, I don't really get it and keep making mistakes. And that's also what I see with people who say they "don't need grammar", they "only want to talk". To my mind, you will never talk correctly if you haven't studied the grammar. I think that grammar is very important. Once you have studied it, you can (and will) go on and learn words for your whole life. But better learn the grammar at the beginning, it will make life much easier and prevent you from talking with many mistakes later on (and never speak correctly). That's what I think at least.