I'm learning Spanish out of necessity and in a very passive way. As I have mentioned prior, my wife is Spanish and thus so too is the other side of my family. Only my wife and one of her two brothers can speak English - and she has a big ass family. When we go over there, I quite often find myself sat on a table with 20+ Spaniards all jammerin' on in their crazy language.
Any advances I make in comprehension comes predominantly from passive listening. It could be an Ni thing, or it could be a 'human' thing. Whatever the case, I'll be immersed in their culture for a week or so without consciously taking much in. Then, I'll have a rapid succession of 'aha' moments / start blasting out perfectly coherent sentences, constructed from various words I've pulled from the back of my mind. This usually takes everyone by surprise, because up until such points I'm just 'w/e-ing' the shit out of everything. Suddenly, I'll chip in to a conversation with perfect Spanish - even on topics I've not actually learned about / previously discussed. This usually has them (especially my wife) WTF-ing like mad.
They find me fascinating, according to my wife. I'm like this weird English curiosity; they think I'm so aloof and quiet because they're all gregarious and loving, etc. But, they are nothing if not an accepting people, so I get to be just that - my grumpy as fuck self, politely ignoring everything/one ^_^
German is a great language - I really took to it in school. I wish you the best of luck on your journey. Learning another language, even by necessity (>_>), is paradigm-shifting on a scale you really can't even begin to imagine before you embark on your learnings.
It's that moment of realisation: "Holy shit - I can now speak to hundreds of millions of people that I couldn't prior". Even the little things, like being able to pick up on bits and bobs of Spanish in American TV shows, or being able to watch Narcos without referring to the subtitles 100% of the time.
Shit be cool, yo.
[EDIT] Or this one (hugely flattering) time where some of my wife's 'rather forward' friends were talking about how handsome I am (I'm not; I'm just very different to them, and have the whole 'big blue eyes' thing they go fucking crazy for) and how they admired her taste / they'd absolutely bang me if I wasn't spoken for, etc. I just stood there, smirking.
My wife turns to me, smirking right back. We lock eyes and have that unspoken confirmation thing happen. She turns back and says (in Spanish, obv.) "Thanks! I'm really glad you find him attractive. You do realise he speaks Spanish though, right?"
I swear to fuck I've never seen a group of people go from 'happy / cocky confidence' to 'utterly mortified' so quickly. Eyes darting in all directions but mine; lowered heads and many apologies muttered. They quickly said their goodbyes and shuffled off awkwardly. I was laughing my arse off about it for ages.