Is this an insult?

My niece is in her 40s but immature for her age. She has a lot of typical philosophical sayings she likes. An example: "It's not a problem until it is.". In other words, don't worry about potential problems or try to plan for them or prevent them, live a worry free life no matter what might be ahead.

Recently she repeated this one to her boyfriend: "Today is the first day of the rest of your life.". She told me his answer is the same for all of her sayings lately: "Edna, that's wisdom. And you're full of it."

I think he is giving her a playful insult. She believes he is complimenting her wisdom. Your reaction?