having somebody yell at us in the office or by making a mistake or losing a bunch of money. these aren't problems that our hunter/gatherer ancestors had. they would get stressed if a lion was coming after them or a bolder coming toward their living quarters. and that kind of stress provoked the fight or flight response. getting you ready to do something. >> weekends! >> yes. but your mother cannot know -- >> there is plenty of stress and adrenaline on stage at the groundlings theater in los angeles. >> does the doctor know that you're out here? >> i'm sorry, what? >> this is improv comedy. and hardly anything that can make you more vulnerable and tap into your creativity.