While I was able to learn Italian "completely" through passive exposure to (seemingly) incomprehensible input, German is still a work in progress. Although I don't advocate "input only," that's exactly what I practice. I have enough experience with passive learning to know that a massive amount of passive input considerably accelerates the road to fluency.
German TV hours (1990-2002): difficult to estimate. I initially wrote 2,000 hours but this is a very rough estimate. It is possible I spent less time on it, German TV was an occasional pastime. I never planned to learn anything. I wasn't trying to learn German - I was simply watching German TV in my free time and only when there wasn't anything interesting on other channels. I took very long breaks, at least 7-8 months every year during several years.
In 1993 I attempted to read my first German book - I personally scribbled the date on the book. I quickly lost interest.
2002-2006 - absolutely nothing
In 2007 I listened through Takeoff in German in two days. I didn't know a couple of words. I read a few pages in German here and there and I watched a couple of movies and TV shows.
2008 - a few movies
I can follow any German TV program, reading feels a little tiresome but I can read advanced texts without the aid of a dictionary. Older literature is a bit of a pain - however considering that I still have to finish a "real" 19th ct novel I can read surprisingly well and without the aid of a dictionary. Legal texts and other specialized areas I never paid much attention to are tiresome but I still managed to use German professionally sifting through financial information. I have recently tested myself on Dialang: listening comprehension C2, vocabulary 820. I intend to also do the other tests while I am still a grammar virgin. I used German dictionaries maybe a dozen times in my life. I am not anti-grammar, anti-dictionary etc. I simply did not care. Most of my German experience involved turning on the TV.
I never attempted to communicate with anyone. I never wrote a sentence in German. My "silent period" was ridiculously long. My brain has been pickling in native German brine but when I attempt to pronounce words and sentences aloud I am not always very pleased with the result.
January 2009 -Jan. 2011 I managed to stick with German for two years. During this time I listened to over a dozen audiobooks and I saw a couple of hundred hours of TV shows. I only read maybe 20 medium-sized books.
2011-2012 some audiobooks, a few movies, TV shows, documentaries etc. No substantial reading of any sort.
2012 -2015 Occasional audiobook.
My experience at the local German cultural institute has taught me that I am judging myself too harshly. Speaking is still my weak point, though. Perhaps I pulled my brain out of the German brine too early or I am simply too old to really shine in a foreign language.