[archduck]

His teaching at Cambridge often had minutes-long silences, in which the class just had to wait for him to conclude his thoughts and resume teaching. It was apparently agonizing for some of his students.

Especially since you probably didn't want to step on his toes by breaking the silence while he still held the floor - he was, after all, forced to retire from schoolteaching after beating one of his slower math students unconscious.

[Wistar]

"The Haidbauer incident, known in Austria as der Vorfall Haidbauer, took place in April 1926 when Josef Haidbauer, an 11-year-old schoolboy in Otterthal, Austria, reportedly collapsed unconscious after being hit on the head during class by the Austrian philosopher Ludwig Wittgenstein."

https://en.m.wikipedia.org/wiki/Haidbauer_incident