It is easier to learn languages when you are younger, but nothing will make you learn like NEEDING to learn.
That's such a TRUTH in every aspect of life!
To some far lesser extent is ongoing curiosity.
As English (to date) is generally the global language of business; I found that the only spoken language I needed/utilized, on any regular basis was NYC-Garment-Center-Yiddish. Certainly folks who live a singular overseas posting have different needs.
In practice, of far greater value than being fluent in other spoken languages is understanding, appreciation, and sensitivity to other CULTURAL backgrounds & collective experiences... the basis for their motivations, actions/reactions, and how those get expressed via facial/body language.
Smiling Eyes are Universal.