"Hugo Hecht, Kafka's primary-school friend who followed him to the Gymnasium, remembered Kafka as a very well-behaved pupil – 'always very pure' – who declined to take part in the normal ribald sexual talk of adolescent schoolboys. He was 'very nicely dressed' but also 'somewhat remote and distant from us'. He seemed to his contemporaries to live, as it were, behind 'a glass wall', not unfriendly or haughty, but reserved. He always responded to conversational approaches and wasn't a spoilsport, but he would never make the first move. He was, said Emil Utitz, 'quiet, shy and a little mysterious'."
Nicholas Murray. Kafka. London: Abacus, 2014, p. 28-9