Why is gymnastics good?
You need core strength (strong abs) for Gymnastics. If you don’t have that, Gymnastics will help you build that up, and with it, many things in Gymnastics will be easier. Strong arms and legs are important too, but core strength is the main thing. You will probably also boost your memory, because you will have to remember your routines, and when to connect skills (round-off to back hand-spring – the rebound {which comes after the round-off} you will learn is the beginning of the the back-handspring.).