CastorTroy answer this one.....a drivers license.....I don't plan on ever driving on an interstate...or in a city, I live on a farm...and only drive to the general store in my very small village...I don't see the need to learn how to control my car above 30 MPH...or what a stop lights colors mean....do you think you'd want to drive on roads with people like that?
Same with RC....I don't fly 3D, I don't have the desire....I fly scale like with scale like areobatics......but there is no promise that your aircraft will always be right side up...won't stall or get hit......If you can't fly into a situations at will, you surely can't fly out of it when you have too.....
I have crewed alot of full scale airplanes.....on a pilot's check ride......the new guy would but a newpaper up over his windshield and close his eyes.....the pilot in command would turn the aircraft a few times then put us in a weird attitude like 45 deg of bank and 15 deg nose down...
ok new guy open your eyes and fix it.......we never planned to fly in that attitude but the drivers knew how to get out of it....
always learn all that you can.....stalls......inverted flight.....unusal attitude recovery both going away from you and toward you.....which is areobatics....you may save yourself your favorite airplane some day.
sometimes you can't plan for things.....near my field a year ago or so a factory that made gas additives blew up....all the aircraft that were flying were hit with the shock wave...some it turned 90 deg in the roll.....no planes were lost...cause the guys were good pilots......then they had to dodge debris.......