Critics of perfection

"In praise of imperfection" means to Rita Levi-Montalcini, Nobel prize for Medicine (1986), praise of man, as an unique being mixed of good and evil, whose greatness and dynamism is in its imperfection. Levi-Montalcini confesses her tendency to exclude herself, avoiding social contacts (a tendency she also improperly attributes to J. Watson). However, how can this be reconciled with a view such as that of Kundera: "Existence is not what has happened... Once again, existing means 'being in the world"'?