I think when learning a language, it definitely helps to be surrounded by native speakers of that language (if the goal is to learn to listen and speak). I've lived in Malaysia and Australia; and I can speak English, Malay and Mandarin (actually, my Mandarin sucks, but I understand enough to know when I'm being laughed at. Lol). I was able to pick up basic English and Malay easily enough without formal lessons, because I was surrounded by people who spoke those languages. Not an hour went by without me over-hearing conversations in Malay, English or some other Chinese dialect. The nice thing about Malay and English is that they both use Roman letters, so I could easily look up new words I might hear or read, and find their meaning. With Mandarin, it's trickier because it's written and read in Chinese characters - which I found intimidating to look at when I was a kid. I needed to ask people what certain words meant when I heard them for the first time.

Yeah, if I decide to learn Japanese properly, it'd be good to learn Hiragana too. That way I'll be able to read texts, and reading helps build vocabulary. It's a shame they don't play more Japanese films on SBS. It always helps to be able to listen to and pick up common speech patterns and nuances. If you hear the word "hajimette" often enough, you soon realise that it means 'new' or 'first time' (or something along those lines).