Nija 250.... Damn, thats a sweet bike!
Well with me, whenever I get into something I am usually scared as hell in the beginning and then I let go of my reservations and have fun with it. Examples: Dirtbikes, ATVs, PWC, driving (yeah, I was scared to drive), welding, etc etc etc. Most of these things I am no longer scared of and have a BLAST doing them. It is just how I am.
Just dont think about it and the consiquences, yea you gotta be able to learn how to shift, balance etc. But if you just dont think about it and do it you'll be rough at first but very soon it comes naturally.
A street bike, be it a 1000 or a 250 is just like a gun, it is only dangerous if you let it be, and I let it be dangerous that is why I sold the old CBR. You should not have a problem at all since you have already ridden dirt bikes and such.
