In my first two years of learning, I was "self-taught" using books, internet, anime, and manga. I quickly learned the standard, polite speech and differenciated it from anime and manga. However, the anime and manga were easily the most entertaining of the bunch to help practice with reading and listening skills. Keep in mind I had no Japanese contacts or teachers available during this time.
The following year I visited Japan for a summer (knowing very well I'll have trouble speaking well, but also knowing I could "get around"). This small visit helped me tremendously. I got a mix of polite and casual Japanese, so I was able to learn a lot.
Some time after that (maybe a year later), I knew enough kanji to play video games in Japanese (Tales of Phantasia for PS as my first). I continued to practice spoken Japanese through chat programs (mainly skype) which also helped a lot. I am currently still at this stage (still playing Japanese RPGs!).
Overall, I've taken my time and slowly learned Japanese purely as a hobby. It is relaxing for me and even helps relieve stress. I actually use small sessions of studying Japanese to help calm my mind between intense study sessions of computer science and calculus/theory/discrete math. Memorization hurts my brain less
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