A teacher opens a whole world
Being introduced to a traditional art can mean being introduced to the culture around it. A teacher may pass on not just technique but also the music, religion, workplaces, and neighbourhoods the art grew up in.
Performance

An Afro-Brazilian master presents capoeira as fight, dance, music, play, survival, and community memory.
Being introduced to a traditional art can mean being introduced to the culture around it. A teacher may pass on not just technique but also the music, religion, workplaces, and neighbourhoods the art grew up in.
A demanding tradition gives a great deal to those who practise it, but the exchange runs both ways. Practitioners have to rise to its level so that they can give something in return.
A movement art can be a dance, a fight, and a game at the same time, rather than switching between them. Because it holds all three at once, it can draw in both dancers and martial artists when it spreads abroad.
A tradition forbidden by law does not have to die; it can keep living in hidden, informal practice. When open practice is finally allowed, the knowledge kept alive in secret can quickly become widely popular.
An activity that began as informal play in the streets can grow into a full way of living, with its own philosophy. In the author's account, that philosophy brings practical and spiritual benefits beyond the physical skill itself.
A practice's rules are taught so the learner can grasp the outlook behind them, not just to regulate behaviour. Once you see why the rules exist, you understand what the whole practice is about.