The problem with learning Japanese is that almost every teacher will teach you to speak like a text book & you end up sounding really unnatural.
I have never studied officially just picked up from living here for 4 years & talking to people. My Japanese is probably not technically as good as many people's (I really suck at studying languages) but I never have any problems being understood in Japan whereas many people I know that speak technically great Japanese can never seem to get themself understood