Fun bit of Dr. Strangelove backstory:
Kubrick couldn't get the always-serious-minded George C. Scott to act as crazy-goofy in the big scene near the end as he wanted, so shut the cameras off and convinced him to run through it over-the-top STUPIDLY-crazy-goofy as possible, as an acting exercise to loosen up and get his mind in the right place, mood-wise. After several dry runs of the scene done that way, Kubrick shouted "Cut!" and called an end to the day's shooting.
Because he actually hadn't shut the cameras off.
It was a set-up he'd arranged with the crew before Scott arrived on set, because Scott intensely hated appearing undignified as a categorical thing, and Kubrick had discovered in previous rehearsals it would be impossible to get him to act "psychologically undone" if he thought there would be a record of it.
Scott got really pissed at Kubrick over the trickery, and stayed pissed at him for the rest of his career.
Slim Pickens was exactly the opposite.
Kubrick had to keep reminding him that the movie was dead serious---the most serious subject imaginable---to keep the yee haw hillbilly vibe that was Pickens' trademark from spoiling HIS character.