There is a fair bit of variation in JRPGs. There's random encounters vs overworld encounters. There are overhead displays and first person displays. There's turn based battles and real time battles, and quite a bit in between. There are JRPGs where the choices you make building your character really affect his performance, and JRPGs where you can make no choices at all.
Play Phantasy Star, Final Fantasy 7, Panzer Dragoon Saga, Shining Force, and Vagrant Story. You won't think all JRPGs are alike anymore.
We are prepared to live in the plain and die in the plain!