Yes your right now you mention it, teachers must have conned us and we must have been watching highlights. Must have been there ploy to keep us in and stop us swinging in the bike sheds which we would always get a bollocking for.
It should also have been summer holidays or maybe they had just finished so maybe it was one of the later missions, but my memory recalls as clear as the day it happened that it was Apollo 11.
The landing itself was on a Sunday night, just after 2000 and the EVA about 6 hours later on the Monday morning