My husband and I work hard not to yell at O when parenting.  However, sometimes it's very hard to avoid it.   
Lately, O has been yelling as a means to interrupt a friend or to argue with her parents that Oreos before bedtime will help her sleep better.  

Yesterday in the car she said, "Mommy, I'm stupid."  

I took a deep breath knowing this was her way of getting my attention.   Then I said, "O, nobody is stupid.  Some people make stupid choices, but nobody is stupid.  What makes you say your stupid?"

Her response, "Because I yell at you."

I said, "Oh sweetie, I'm sorry.  I yell at you sometimes too."

Giggling O says, "Mommy, you're stupid."  Kindergarten SUCKS!