One day, my daughter, who has a sharp tongue she's rightfully proud of, came back from school and complained about a bad joke someone had made about her. I said, “but you’re always making tough jokes about your friends, and you say they like it when you hit them with a hard joke that takes them down.”

My daughter said that was true but this person had gone too far.  My wife sympathised with our daughter and told her not to stand for any nonsense.

My input: I told my daughter that if she couldn’t take it, she shouldn’t give it.

My daughter did not  appreciate my advice or my tone.

That advice that was given to me when I was young,  it’s been given to hundreds of millions of other kids all around the world who like to flourish within the rough and tumble of schoolyard.

The same advice applies to President Donald Trump.