Here would be my "back in your face" response... (not sure I would actually say it... but I could think it!)
"It is nice to be Financially Independent! I can pretty much do as I please. Right now I have decided to not work. Yes I have a good education and great career prospects in my field... but DW and I have decided to step back from the rat race and smell the roses. We are going to do some traveling while we are still young, fit and able to enjoy it.
If I decided to go back to work later, I could do it. But I have options, and right now my choice is carpe deim! It is wonderful to be "financially independent" and have the choice to do as one pleases... "don't you think?" What are your goals for the future? [Push the focus back on him to layout his bright ideas for the future... what are your plans @$$h0!3]