Finger

His fingers were preternaturally long and thin; during a peer evaluation of a training lecture he had given, a fellow student had commented that when he pointed with his index finger, he looked like a skeletal Angel of Death. That comment left him self-conscious about pointing, and he quickly came up with an alternative. Rather than extending his index finger fully, he would bend the finger at the joint, using just the proximal phalanx bone when pointing. He had immediately found this motion awkward, but when he positioned his thumb tight against the phalanx, he realized he had hit upon the position he had been seeking. That motion of his, pointing to students with his thumb tucked into the middle of his bent index finger, had become his signature gesture, imitated by students both in mocking contempt and fond admiration. He was especially pleased when students would return for a visit and greet him first with his signature half-point.