“We can never know what to want, because, living only one life, we can neither compare it with our previous lives nor perfect it in our lives to come.”
The author often alludes to Friedrich Nietzsche's concept of “eternal recurrence”: human life must occur not for once, because in such case it means nothing, no matter how beautiful, successful it was (the German proverb “einmal ist keinmal” [one time means nothing]). And in this phrase the author also hints that a man is actually helpless in this world, ‘cause he/she lives it for the first time, without any repetitions. Moreover, Kundera says that our life is actually the very first repetition, but the second will not happen with us, and this is the worst.
“To love someone out of compassion means not really to love.”
This phrase concerns the relations between Tomas and Tereza. Tomas has the feeling of compassion to Tereza: it hurts him seeing how she is suffering because of him. But this feeling supplants the feeling of love to her, ‘cause love must “feel” free in order to exist, but Tomas doesn’t have this freedom – he is “pressed down” with his obligation to Tereza.
“A person who longs to leave the place where he lives is an unhappy person.”
The narrator hasn’t addressed this phrase directly to anyone of the characters. And it’s clear: it concerns everyone in the story – all the characters often leave their places of living. They have money, love, etc, but the reader feels that anything makes them happy, the lightness of being is unbearable for each of them.
“A man who loses his privacy loses everything.”
Sabina always followed this rule. She “despised literature in which people give away all kinds of intimate secrets about themselves and their friends.” They are monsters, as for her, because they give their lives up of their own free. That is why she always kept her love in secret, that was her method of “living in truth”.
