Pol Pot had a thirst for power. He was introspective, self-effacing, and displayed self-control. He was also highly reclusive, obsessed with secrecy, and fearful of the threat of assassination. He was often in control while pretending not to be; Short stated that he "delighted in appearing to be what he was not – a nameless face in the crowd". During his political career, he used a wide array of pseudonyms: Pouk, Hay, Pol, 87, Grand-Uncle, Elder Brother, First Brother and in later years he used the pseudonyms 99 and Phem. He told a secretary that "the more often you change your name the better. It confuses the enemy". In later life he concealed and falsified many details of his life. He never explained why he chose the pseudonym "Pol Pot".