Rav Yankel Cohen zt”l, whose yahrtzeit was marked this week, is seen in a chair at the dentist office of Dr. Jerry Friedman on a Friday morning to be treated for a tooth abscess. After Dr. Friedman administered the Novocain and a mask for laughing gas, Rav Yankel looked at his watch, saw that it was 11 a.m. – when he normally gave his Friday shiur to talmidim – and proceeded to give his shiur to his daughter on the phone, unable to contain himself.