His feelings for the Czech journalist Milena Jesenská became the most vivid experience in the life of the ‘Prague genius.’ Their romance didn't last long, but their correspondence continued for several years. It was to Milena that the writer entrusted his diaries and the later famous ‘Letter to his Father,’ and their complex, emotional relationship was reflected in Kafka's main work – the novel ‘The Castle.’ These unanswered letters partly resemble a friendly correspondence, filled with anxious thoughts, fears, painful experiences, and deep mutual understanding.