Not an Oscar Wilde fan myself. And it certainly would seem that, while he followed his own advice, that he likely should’ve followed the advice of some folks here as well. ;->
That said, his statement above was likely framed the way it was because he wanted to insult you (me, everyone). It’s a challenge. Did it make you feel defensive? Likely yes, and if so, that’s an opportunity to be introspective about your life and motivations. But also because he wanted your attention, your angst and ire. If you allow yourself to react passionately without cold reason and logic, then you won’t have the chance to learn the lesson that he has to share, not just his words, but actions, too.