When we were little, we had a code word. In case someone other then our parents had to pick us up, they had to know the word.
My Mom was busy doing something one day, so my Grandfather said he would go get us. I threw a hissy fit (just being a brat) in the school parking lot because he didn't know the word. He finally leaned down and whispered "Get in the f'n car NOW!"
He's 80 now and I still tease him about how awful he was to yell at a scared kid