It's amazing the power of these sort of sessions though.
One of the only assemblies I remember from secondary school - would have been 4th/5th yr so c. 1985 - was delivered by the deputy head.
As we filed in, girls were directed to one side of the hall, boys to the other and he went on to explain that a change in the law meant that from then on, boys would get academic schooling, but girls only a couple of hours a day learning childcare/cooking/sewing etc
Ridiculous now, but he must have done it well, as we all swallowed it and there was outrage on both sides.
All sorts of classes the following week used it, for discussion on changing social history, influence of people in power etc. Was powerful stuff.