Mind Blowing
This I believe, based on my own experience and that of native speakers of other languages who have cracked tonal languages. After about two years of stumbling and fumbling idiotically with Chinese on a daily basis, something weird occurred inside my head. I can liken it only to the impression conveyed by the Buddha statues that show the Buddha manually splitting his head apart to reveal another, true self beneath.
I recall waking one morning and finding everything suddenly and very unexpectedly in place. I had resigned myself to accepting that I would never achieve any reasonable level of fluency, since I was stubbornly stupid, lazy, and completely lacking any sort of innate flare. But one day, it all just came rushing together. Then came Japanese – reading Japanese with years of Chinese behind drastically simplified the challenge. Weirdly, I now use Chinese on a near daily basis, but while in Japan, years would go by without my speaking a word. Tonal languages utilise both brain hemispheres. I believe I have benefited hugely from this expansion ever since. Use of both hemispheres allows for far deeper processing. I would never have developed an interest in art, philosophy, or poetry had I remained confined inside my left hemisphere.