How does it work when an actor is both directing and starring in a film?

There have been a number of actors who both directed and acted in a film, so I was wondering how they actually do that. Surely you can’t act and direct at the same time?

This may seem like a stupid question to most of you, but I’m exhausted at the moment and tiredness makes me stupid.

Ok, surely they can act and direct at the same time.
Thats exactly what they do. Being a director doesnt mean you run the camera the whole time. To tell everyone what to do and then watch the take on the little tv after its done to make sure it came out the wy you liked it. ONly prob is you cant be behind the cam but it usually comes out the way you like it becasue you hired the right camera crew. Its just extra work becasue you not only worry about the movie but also you being the main actor. Its extra work is all but I can do it and its kind of fun.