The first thing i learned is that Actors have the most difficult and the most dangerous job on the set.
I would have thought it would have been someone using heavy equipment or someone running the rigging.

Second thing is  Actors, in order to do their best work, must be working in a safe environment.
I didn't think this because some of the sets in movies look kind of dangerous but it is still good acting. That could just be cgi but you never know.

last thing is that while taping only the director should be talking to the actors. I thought that most of the people on the set would have to talk to the actors for safety reasons but i guess not.