It's a well-written, but impossibly boring book about nothing. It feels as though the author wrote for the sake of writing. The characters are uninteresting; everyone is extremely nonchalant to the point where it seems like they are all disconnected from the world, although that likely wasn't the writer's real intention.
I love Kundera’s books—he's one of my favorite writers—but this book is a huge letdown. Maybe one or two phrases will stay with you, but you could say the same about Winnie the Pooh.