There are two kids per episode who change their hobbies each other. The "hobby kid" teaches the "change kid" and trains with him; for some time the change kid learns alone the "change hobby". After a agreed time (e.g. one week) both kids have to pass the exam what they have learned from the change hobby.
Bilo je na kanalima:
Kad jaganjci utihnu 
Državni posao 
Garfild 