> The book asks, even in the face of that kind of cynical and over-intellectualized view of the world, why and how do we try to find meaning in our lives regardless?

This. I don't get the sense that Kundera himself is advocating for either lightness or weight. The novel asks a question that's as much philosophical as it is psychological, and the beauty lies in the question itself rather than any answers.

To quote Kundera: "On the surface, an intelligible lie; underneath, the unintelligible truth."