I really don't think Milan Kundera is an author for me. His characters are all so petty and cruel, so atomized and self-centered. I can deal with pettiness and cruelty being a theme of the book - but everyone? All the time?
And if he were trying to say something about life in a country under a totalitarian regime, that might be one thing (although I'm quite sure not all glimpses of humanity, of kindness would entirely disappear) but the outsider character is just as careless of others, just as petty and distant.
Two characters come back to Budapest after years of having lived in other countries, having put down roots there. Irena and Josef meet, and she remembers him, while he only pretends to remember her. The book travels through their experiences as expatriates returning to a country they dislike.
No one in this book listens to anyone else, and yet feels injured when the people they're with don't pepper them with questions. Not willing to give, yet bitter about not receiving. Some of the sections about the difficulty of homecoming were interesting, but undercut by no one in the book having any kind of self-awareness about this. The main character, Irena, is simply irritated that everyone wants to tell her about their lives instead of hanging on every word about hers. But there is no sense she listens to them, either.
Memory is also a huge theme, but mostly in the sense that people actively forget the times they've been mean, in order to live with themselves.
This is a book about spaces, gaps, not knowing each other. Everyone is constantly perceiving petty slights, and going out of their way to inflict petty slights on others.
The only character any other character seems to have actually connected with on any deeper level is the dead one, so we don't really know what that relationship was like. Ignorance is beyond pessimistic about human nature - it seems to enjoy inflicting small wounds on everyone. All the time.
Not for me.