are polyglots kino?

Is learning a very different language from your mother tongue the single best thing you can do for yourself? Having to do something really difficult and stick with it every day while keeping chin up in the face of underwhelming results and little linguistic "gotchas" has imbued me with the following benefits
>improved discipline
>better focus
>constant self-critique and improvement loop
>healthier and more productive mindset
>flexing on uniglots
Nothing else has had such broad waterfall effects on my life, and this in addition to all the well studied cognitive benefits of learning a language.

whom are you quoting?