This question is lifted from author Sahar Sabati's informative Ask an Author series, which ran from 2015-2016 and included responses and reflections from English-speaking authors from around the globe. Since I'm often asked these questions by readers, I have republished my answers here with Sahar's kind permission.
My biggest failure. This is a great question. I’m excellent at failing so it’s hard to pick just one! One of my keenest regrets though, is failing to learn Cantonese—my mother’s first language. Later in life, I learned to speak French, and of the insights into a people and their culture which can be achieved through understanding the language. So while being bilingual is a good thing, it has lead me to understand that by not speaking Cantonese, I am missing a part of myself.