My mom slapped me in the face when I was in my late 20's . Can't even recall what I said to her but it wasn't that awful and surely didn't warrant that reaction.

My mother once slapped me across the face in the grocery store when I was in my early 20s and I asked her why she hit me and she said she didn't like what I said. I asked her if her friend, So-and-So, said something she didn't like, would she hit her? and she said she wouldn't so I said "then why would you hit me?" It actually made an impression on her.

I smiled, said thank you and nothing else.

when he was 6 yo, is one thing I have regretted for 80 years.
Shortly after separating from my ex, I had said something that he did not like, so he stomped his foot, looked at me and said, "You, Stupid!"
I reacted before I thought! This was something he had seen his dad do so many, many times.
It took a long time before he learned that the word stupid is is not a 'bad' word; but, to call someone "Stupid" is.

Son recently sent me an email showing a cup with 'Mother is always right' on it.
I replied with a pic of my key chain that bears the slogan, "Oh shit! I have become my mother!" Thus, it is his Grandmother who was always right.