the center of attention, and with his almost electric charisma, grabbing the attention of the people around him. He was also extremely manipulative; with his formidable intelligence, he was capable of manipulating a person or a group of people without much difficulty. In addition, he was repetitive and obsessive. In discussions with his colleagues or foreigners, he would repeat the same things over again on a continuous loop until they were convinced he was right. It was absolutely impossible to contradict him on any subject whatsoever. Anyone who attempted to convince him that he was wrong or even making a suggestion that it could be improved slightly was making a "fatal error". Fidel would then make a mental mark of the individual as an "idiot", and would wait for the right time to retaliate against them. Nobody, not even Raúl was exempt from this; despite being the minister of the armed forces, he would bring seemingly minor military decisions to Castro for his final approval in order to avoid inadvertently contradicting him. Sánchez believed that General Arnaldo Ochoa's downfall was significantly related to his willingness to contradict Fidel's orders in Angola. Biographer Leycester Coltman described Castro as "fiercely hard-working, dedicated, loyal ... generous and magnanimous" but noted that he could be "vindictive and unforgiving". He asserted that Castro "always had a keen sense of humor and could laugh at himself" but could equally be "a bad loser" who would act with "ferocious rage if he thought that he was being humiliated". Publicly he was known for throwing tantrums, and could make "snap judgements" which he refused to back down from. In private though, Castro was actually skilled at keeping his anger in check and not allowing it to affect his judgement, simply becoming cold and withdrawn; Sánchez stated that in 17 years he had only seen Castro explode in anger twice, one upon being informed of his daughter Alina's defection in 1993. Castro was known for working long hours; he primarily woke up late – rarely before 10 or 11 am – and started his working day around noon, and would work until late at night, often only going to bed at 3 or 4 am. He preferred to meet foreign diplomats in these early hours, believing that they would be tired and he could gain the upper hand in negotiations. Castro liked to meet with ordinary citizens, both in