The (in)famous astronomer Tycho Brahe died from a bladder infection after politeness prevented him leaving the audience on such an occasion.

https://en.wikipedia.org/wiki/Tycho_Brahe#Illness,_death,_an...

Indeed! It's said that no talk should be longer than a microcentury.

https://www.ams.org/notices/199701/comm-rota.pdf

https://susam.net/microcentury.html

Nice one! I would've said half a microcentury would be the perfect limit for most school lectures, but for an engaging talk a full microcentury would be acceptable :-)

> if you talk for too long that is

I've made that mistake. Talking for longer than 50 minutes is a bad idea.